Maybe you don't have to kill Salem to save the world

I've been thinking about this theory for a while and it makes a lot of sense. In season 6 (I think) the knowledge lamp or whatever said that Salem what turned evil after going into the bad liquid in the underworld, and the other brother's home had holy water or something, so maybe if Salem went back into the holy water (maybe by force) she would be healed of the grimm juice and be nicer. Also the only time that she went evil was when she had grimmness in her. This is not a big theory, actually it's a hypotheses, so please no hate.