You could also try a C02 cleaner, the molecule attaches itself to uric acid in urine (which is what produces the ammonia that you smell) and oxidizes it, which removes the stain and smell. I've used Fizzion around my home, works like a charm! http://fizzionclean.com/why-it-works/%3C/p%3E (http://fizzionclean.com/why-it-works/)