I have to bathe MooShoo (my hairless cat) at least 2-3 times a month. The reason being he has no fur for the oils to soak into. The telltale sign is a ring around his neck.

Now, don't laugh, but when I DO bathe him, I get into the tub with him. I face him away from me to give me more control. I put a small hand towel underneath him so he doesn't feel like he's slipping.

He's not crazy about it, but knows it's necessary.

I don't bathe any of my other cats unless they get really dirty and smelly, or they are being shown in a cat show. I do the same thing with them as I do with Moo, i.e., getting in the tub with them.