My beloved husband put Thompsons Waterseal on a concrete patio underneath a deck. The concrete had been finished with a sealer after we had it pressed to look like tile. I know the guy who did it applied some kind of sealer at that time. The patio is now as sticky and gooey as glue and very slippery when it gets wet. I have pressure washed it several times, tried to clean it with a commercial cleaner, applied dry dishwasher detergent on a wet surface and scrubbed it with a broom. It is still as sticky and oily as before. I posted a notice on DIY and one man suggested that I contact Thompson's for suggestions. He also suggested paint thinner and muratic acid, both of which scare me. Does anyone have a suggestion?