Bevendre

Until they’re released, yes.  Bev’s spell came with a charm that would release should the victim not be tied to a ball.  So long as they can be recalled the spell remains in effect, but would wear off over time if the Pokemon was set free. 

As for Bev during the bad end……not quite.  Since she was turned with a reflected spell that charm was broken, and her own transformative properties were redirected from her spray to her slime.  So long as she keeps oozing on herself she won’t turn back, and those she covers may end up like her.