Pink Solution is incredible at removing hard, set-in stains from any surface. What we recommend is to apply Pink Solution Heavy Mix to the stained area and scrub rigorously with a sponge. Leave this treated region for up to 3 hours. After some time, come back to the region with a wet, abrasive scrubber and apply the scrubber directly to the bucket of Universal Scrub (Previously Mothers Choice). Proceed by scrubbing that previously treated region with Mothers Choice. After Mothers Choice has been used, leave for about 30 minutes and then rinse clean.