|Bigger version of this 1941 ad here|
Because perspiration is acid. Acid is perspiration. They are one and the same. And do you know what acid does? And perspiration? They eat stockings, that's what. For breakfast, lunch, dinner and the occasional between-meal snack. They live to eat stockings.
And when that happens, Bob is going to find out. And do you know what Bob will do to be helpful? He will give you a pretend-surprised look - he is subtle, that Bob - and say "Another run?" Another one, dear? Goodness, you really are full of acid today.
And then the tiny Ivory Soap Fairy will jump, seemingly from Bob's pants (best not to inquire too closely into that), and insist that you use her Ivory Soap Flakes to combat this terrible problem of yours. They will also give you "lovelier hands." Yeah, because your hands are also lousy. You'd probably better wear gloves while you wash the stockings. And then wash the gloves. Or maybe you should just send the laundry out. You can send Bob out to the laundry, too, when you do. Maybe they can wash his mouth out with Ivory Soap Flakes so he'll say something better than "Another run?" next time there's a problem.