I have a dog bath, too, and it works quite well, although I've rarely used it. I have very limited floor space inside, but can make it work in a pinch. The dog bath does not have to be expanded to its full diameter, which is helpful. A gray Sterlite tote has been fine for washing my hair and sponging off.
My set up uses a marine bilge pump, but the concept is the same. I got tired of replacing the purpose-made 12 volt submersible pumps. A thirsty marine sponge is great for wiping out the dog bath or tub.