Using TSP as a cleaning solution requires you to wear suitable clothing, hand and eye protection. Use TSP for washing surfaces prior to painting, especially outdoor surfaces.
Dilute TSP in a ratio of 1/2 cup TSP to 2 gallons warm water for heavy cleaning, and 1 cup TSP to 3 quarts warm water for extreme cleaning. When cleaning requires killing mildew, add household bleach to the TSP and water mixture. The recommended ratio is typically 1 part bleach to 4 parts water, but the manufacturer's mixing ratio may vary and should be consulted.
Apply TSP with a brush, sponge or spray, and use some elbow-grease remove stains. Due to TSP's ability to stain metal, etch the glazing of ceramic tiles and attack grout, do not use it in bathrooms.