How to make a scrub for sinks and tubs

For most sinks and tubs, the published homemade scrub is plain baking soda or salt on a damp sponge, used "as you would scouring powder" (University of Georgia), or a creamy paste of borax and castile soap that Georgia calls a non-abrasive soft scrubber. NMSU adds a vinegar-based powdered cleaner with a choice of five powders, from chalk for "a mild, nonabrasive cleaner" to pumice "to remove stains or polish surfaces." This page sets each one out as published, ranks the powders by how the sources describe their grit, says which fixtures the sources name as safe for which version, and covers the one question none of them answers: how to keep a paste from drying out.

Pick the powder by how hard you need to scrub

NMSU describes five powders for scouring, each to be combined with vinegar [1]. Ordered from the gentlest description to the strongest:

The sources do not rank these by hardness, so the order above follows their own words, from "nonabrasive" through "mild abrasive" to "remove stains or polish." Baking soda and washing soda explain the difference between those two, which share a box shape and very little else.

NMSU's powdered cleaner

As printed in NMSU's G-313 [1]:

Combine 1/2 cup vinegar with 2 tablespoons: - Baking soda to absorb odors, deodorize, and as a mild abrasive. - Chalk for a mild, nonabrasive cleaner. - Pumice to remove stains or polish surfaces. - Salt for a mild abrasive. - Washing soda to cut heavy grease.

Our note: baking soda and washing soda both react with vinegar. Baking soda and acetic acid react one to one to give sodium acetate, water and carbon dioxide [3], so expect fizzing and expect part of each ingredient to be spent before it reaches the sink. If you want the grit of baking soda and the acid of vinegar, the Georgia method below, which uses them one after the other, gets more from each. Mix the vinegar versions in an open bowl, never a closed bottle, because the reaction gives off gas. Combinations that cancel explains when fizzing does useful work and when it does not.

Georgia's dry scour for tubs

Georgia's Tub & Tile card uses vinegar first, then a dry powder (revised October 2018) [2]:

TUB & TILE CLEANER - white vinegar - baking soda or non-iodized salt To remove film buildup on bathtubs, apply vinegar full-strength to a sponge and wipe. Next, use baking soda or salt as you would scouring powder. Rub with a damp sponge and rinse thoroughly with clean water.

UF/IFAS gives the same idea for refrigerator interiors: "Rub hard-to-clean spots with dry baking soda" [4]. A plain sprinkle of baking soda on a damp sponge is the simplest scouring powder in any of these sources, and it needs no recipe at all.

Georgia's non-abrasive soft scrubber

For a paste that clings to a sponge, Georgia's card [2]:

NON-ABRASIVE SOFT SCRUBBER - ¼ cup borax - vegetable oil based liquid soap - ½ tsp. lemon essential oil In a bowl, mix the borax with enough soap to form a creamy paste. Add lemon oil and blend well. Scoop a small amount of the mixture onto a sponge, wash the surface, then rinse well.

The same card is in Kentucky's and Missouri's sets [5][6]. Georgia identifies the soap as castile soap and borax as "sodium borate" [2]. Borax deserves respect around small children and pets; borax sets out how US and EU agencies classify it. Rinse the surface well, as the card says, and store the paste out of reach.

Which surfaces the sources say each version suits

The sources name surfaces only for a few of these:

• Dissolved baking soda for delicate fixtures. Georgia's Plumbing Fixture Cleaner #1, "2 tbsp. baking soda" dissolved in "1 quart (4 cups) water," is for "stainless steel, chrome, fiberglass, ceramic, porcelain or enamel fixtures," wiped on and rinsed [2]. Dissolved, the soda has no grit left to scratch; the card does not give its reasons, but that is the practical difference from a dry scour.
• Dry baking soda or salt for bathtubs, after a vinegar wipe, per the Tub & Tile card [2].
• Very fine steel wool with baking soda inside an oven, from NMSU's oven method: "Rub gently with a very fine steel wool pad for tough spots" [1]. That is written for an oven interior. Do not carry it over to glass cooktops, fiberglass or acrylic; ovens and stovetops covers cooktops.

Your cloth matters too. UF/IFAS says to make cleaning cloths from soft material, but "first remove buttons, zippers, and anything that might scratch surfaces" [4].

The vinegar in the NMSU powdered cleaner and the Georgia tub method limits where they can go. A stone restoration specialist quoted by Stone World explains that acid etches calcium carbonate stone such as marble and travertine [7], so keep vinegar scrubs off marble vanity tops, travertine and other calcium-based stone. For acrylic tubs, fiberglass showers, enamel and stainless sinks, check the manufacturer's care sheet first, then use the sourced surface table on matching the cleaner to the surface. Try any scrub on a hidden spot before the whole surface.

Keeping a paste from drying out

None of the extension sources addresses storing a paste, and none gives a shelf life for one. What they do say points to one answer: make a small amount and use it. UF/IFAS's general rule is "It is best to mix just what you need and use it all" [4], and Georgia's soft scrubber directions are written for a single bowl's worth, scooped straight onto a sponge [2]. A borax paste that has dried in the bowl can be loosened with a little more liquid soap, which keeps you within the recipe; adding water or other ingredients makes it a different, untested mix. If you do keep some, use a small lidded jar kept for cleaning, labeled with the contents and the date, and never a food container, which both UF/IFAS and NMSU forbid [4][1].

Taking a scrub to the tub, tile and toilet

A scrub handles the grit. Soap scum and hard-water spots usually need the acid side of the job, which comes with its own limits on grout and stone. Bathroom, tub and tile covers that next, and toilet bowls covers the one place in the house where scrubbing powders and bleach most often end up together.

References

1. New Mexico State University Cooperative Extension Service (revised by Rick Griffiths and Sonja Koukel), *Green Alternatives to Toxic Household Products and Hazardous Waste*, G-313, revised February 2019. https://pubs.nmsu.edu/_g/G313/index.html
2. University of Georgia Cooperative Extension (Pamela R. Turner and Sharon M. S. Gibson), *Green Cleaning: Recipes for a Healthy Home*, HACE-E-73-1 (Green Clean Booklet), revised October 2018. https://site.extension.uga.edu/greenway/files/2024/09/10.18_Green-Clean-Booklet_update.pdf
3. Science Notes (Anne Helmenstine), *Chemical Equation for Baking Soda and Vinegar Reaction*, updated August 26, 2023. https://sciencenotes.org/chemical-equation-for-baking-soda-and-vinegar-reaction/
4. UF/IFAS Extension (Amanda Griffin and Randall A. Cantrell), *Homemade Household Cleaners*, FCS3319, Release Date October 7, 2025. https://ask.ifas.ufl.edu/publication/FY1449
5. University of Kentucky Cooperative Extension (Connee Wheeler, adapted from Gibson and Turner, UGA), *Green Cleaning: Recipes for a Healthy Home*, HHF-CRW.175, January 2010. https://fcs.mgcafe.uky.edu/sites/fcs.mgcafe.uky.edu/files/green-cleaning-recipe-cards.pdf
6. University of Missouri Extension (Pamela R. Turner and Sharon M. S. Gibson, adapted by Kandace Fisher-McLean), *Green Cleaning: Recipes for a Healthy Home*, GH201, 2019 (GH-0201-2019 in the MU MOspace record), adaptation of the 2015 UGA edition. https://extension.missouri.edu/media/wysiwyg/Extensiondata/Pub/pdf/hesguide/foodnut/gh201.pdf
7. Stone World (Jason Kamery), *Stone Care Expert: Chemical Misuse Voids Warranties, Damages Countertops*, December 18, 2025. https://www.stoneworld.com/articles/95388-stone-care-expert-chemical-misuse-voids-warranties-damages-countertops