I asked him. He doesn’t know what actual kinds of treatments were done in the salt mines. His mother worked at some place (don’t know what kind) where the employees had a sort of vacation thing, many factory workers had the same. Part of the benefits was a ticket to go to treatments in the salt mine which was nearby. Sort of a rest/recuperation vacation. Some workers took advantage of it, some just sat around and drank and played cards. His mother went to the treatments but she’s gone now and he can’t ask her for details.
Thanks LJ.