Depending on how bad you want it....you can use a child's swimming pool or a metal farm tank or even ask to borrow a friend's or relative's tub. People are very understanding when they have a guest bath and you tell them it's for health reasons. Well, at least they are understanding until you don't clean the tub after you are finished.
Perhaps if you get a chance to go on vacation sometime, you can rent a hotel room with a bath and give it a good try. I personally like spa vacations.
Hmmmm, putting acid on top of already too acidic skin. Yeah, I don't think it would work too well either. ACV does soften the skin very nicely, but if you want to draw out a lot of acids not only from the skin but from deeper into the lymph system, the alkalizing baths are great.