while i don't think it is technically a word, "rehabilitatee" makes more sense than "rehabilitator"
rehabilitator would be someone who facilitates rehabilitation, note someone who receives it.
anyone else remember when this manga was lewd and sadistic? somehow it has been shifting into wholesomeness
the mangaka has us right where he wants us!
doesnt "aisu" (ice) mean "ice cream"? i.e. a shortened version of the loanword aisukurimu (ice cream)
that would make sense why the guards didnt know what he was talking about, as ice cream doesnt exist in their world