If you go in the way back machine, people used Ivory soap more than any other kind on the planet........ and yes, it was their shampoo too. This would be around before the point of 1945 or so. Anytime before that for probably lordy knows how long, Ivory soap was shampoo.
Considering shampoos were created to defeat the yucky hair soap gave, right there should be your answer. Ivory in particular, though popular, is harsh as heck on hair.
Bookmarks