I really do feel for you. I had a cat (or two) that peed on my toothbrush repeatedly and on on a small TV until it no longer worked. Vet work showed no problems.

I used an enzyme cleaner every time I could and eventually the peeing stopped. I always have a gallon of Simple Solution Cat Spray and Urine remover on hand. I'm generous with the amount I use and even wipe down hard surfaces with it.

Could Minion be upset about some minor change in the house?