Just my opinion but that's crazy!
Read through the tons of posts that ask how to get rid of the bubbles that result from soap residue in bathing suits. You would have to drain the tub..I can't imagine all those bubbles would be good for anything or anybody. I also know sometimes bubble baths can often be drying and irritating to children. Combine that with hot water...you could never manage water in that condition either..
I wouldn't do it. Keep the bubbles in the bath tub