I hope you get better solutions than mine. I didn't have this condition when I cruised, but I did a hiking trip in Switzerland in the fall and had to figure something out. I took a silicone foldable bowl, a new cleaned quart thermos, a small bottle of dawn and one of the coiled wire heaters. The bowl worked well for soaking. The little coiled thing quit after a couple uses. In one hotel, I had electric kettle. In another, the kitchen staff graciously gave me very hot water in thermos I'd use in silicone bowl for soaking-2 trips each cleaning. I was able to get vinegar at last place. I think you could take vinegar on board. My solution wasn't ideal, but did my best. Good luck and enjoy!