Maybe this should be in Jokes and Humour.
Don't laugh, I had to buy a new washing up brush. SWMBO asked me to wash up a bowl of something she found in a cupboard.
I tried neat washing up liquid to start and after several other attempts including turps and meths. I gave up.
Nothing would disolve what ever it was and the brush and my hands were covered in a really sticky goo.
Nothing for it but to throw the bowl and brush away. It took 2 days and numerous washes to get it off my hands.