So far, I’ve found two ads in 1947 newspapers for products that claim to help some women, but not all.
First, there’s this ad from the June 11 1947 Toronto Daily Star, in which 9 out of 10 women get to have their hair glorified:
And the November 6 1947 Toronto Daily Star has an ad for a product that offers lovelier skin for 2 out of 3 women:
Putting on my nerd hat: if we assume that the two products are independent – if there is no correlation between hair and skin improvement – calculations indicate that 3.3% of women receive no hair or skin help from these products. Pity these unfortunate few!