Hello, we have exactly the right sponge for your fathers really delicate skin and that is the Sea Wool. I would recommend getting two of them, because they will be more hygeinic if they get to dry completely between uses and they are quite slow drying. If you have two, you will be able to alternate their use. It would actually work out cheapest for you if you buy a 4 inch Sea Wool sponge and once it is wet, cutting it in half!