You can find the powder form at Lowe's, Walmart, Home Depot, etc. and any paint store. There is also a liquid form too. Usually sold with the name of TSP on the box. It is used by the barrels full commercially. Did you know Trisodium phosphate is commonly used as a food additive? It's the same stuff they took out of the detergent. LOL This is straight from Snopes:
Trisodium phosphate, a food additive common in cereals like Lucky Charms and Cheerios
Read more at http://www.snopes.com/food/ingredien...GQXbr601TMZ.99