Important: - Always test on a small area before general application. 

For Mild Cases

1. Dilute 1 part Grout stain remover to 4 parts cold water.
2. Apply to the surface using a cloth or sponge.
3. Wipe off using a clean damp

For More Severe Cases

1. Dilute 1 part grout stain remover to 1 part cold water
2. Liberally apply to surface, agitate with a nylon scrubber.
3. Leave for 5 mins and keep wet using additional solution
4. Mop up and rinse with clean cold water

For Extreme Cases

1. Use undiluted 
2. Agitate using nylon scrubber
3. Mop up and rinse thoroughly using clean cold water