Trisodium phosphate

Trisodium phosphate is a powdered cleaner for heavy cleaning jobs: very dirty floors, grimy walls and ceilings, kitchen grease, soot marks. Dissolve it in hot water and wash with a sponge or a scrubbing brush. It is the product used to wash down a room before repainting it.

It comes in a 900 g tub of white powder, fully soluble in water. It is an old-fashioned hardware store product, unscented.

Handle it with gloves and keep splashes away from the eyes: it is an irritant, not a gentle cleaner. After washing, rinse with clean water, especially before painting. Test it first on an inconspicuous corner of painted surfaces, as it can dull them.