Most hides that are conventional are very irregularly shaped and are for decor. For a tub that is obviously not required.
It's a ceramic cup.. he can't knock it over but he likes to slide it all over the cage.. which will cause the water to spill out of any water bowl. :]
Paper towels are much cheaper and easier to regulate temperature in, and personally I've found paper towels to be easy and effortless to clean.
I don't mind investing in a hide for him, I'd like to be able to make one though so when he's older, I can continue to make them as he grows. It's just finding a hide that fits in a tub without being.. well.. obnoxiously pointless.