KAK - I have been using that exact soap (I went and checked when I read your other thread) and it isn't working. I think she might need something stronger than that.

I already had bought all stainless steel and glass bowls that I clean out all the time now, when Tilly got the first ulcer. The vet thought that might make the problem go away, but alas.. it didn't leave! But I don't have any plastic anymore for them at all. When I travel though I have to have something with a lid.. I wonder if plastic every once and a while is ok? I use like glad ware or ziploc containers, because they are cheap and they have a pretty good and tight seal for the water.