You say, Combe has surely changed the formula, but Combe denies it, at least according to this 2013 thread that I assume most long-time members here are aware of: Combe has NOT changed Williams Mug Soap! (Case No. 490334) - https://www.badgerandblade.com/forum/threads/combe-has-not-changed-williams-mug-soap-case-no-490334.357664/Actually, they are required to list everything in the soap. Salt has always been used in the production of soap. It was there before but probably not listed. Salt is what is used to get the soap to fall out of solution during the manufacturing process. I watched my grandma do it when I was a kid. Combe surely changed the formula, but the addition of salt was not the change. Only listing it on the package would be required now.
Is it possible that Combe merely modernized or streamlined some aspect of its production machinery and/or methods and now produces, if unintentionally, a harder, drier puck, despite using the same ingredients?