50 years ago my friend's father used to put Omo soap powder in his bath. When the bath water drained off the back yard got a cleaning as well .... So much foam.
My DH had a brother with a very sensitive skin. He was advised to put unscented soap in his bath. This was back in the late sixties. (His brother sadly died of kidney disease in the early seventies). The only thing that was suggested by the doctor was 1001 carpet shampoo, so he used that!
Having run out of nice smelly bath gel etc, i thought, oh well, a squirt of hand scrub would do. Not a good idea, it arrived in the bathwater like a shoal of little pink worms Still not one to waste a barhfull of hot water, i ventured in. Probably now have well scrubbed parts that other bath gels don't reach.