My Enchantress likes to toss Mass Control at me while I'm in town (no demons around). She also likes to throw it at me while I'm really far away from demons, am running away from them, or after I've killed all of them. All in all, whenever they are not in range to be effected by it, or are no longer/not around, she will use it. I think it might work successfully maybe half the time, but that's being optimistic.
I also find it very unamusing to read other threads citing Mass Control turning YOU into a chicken. It's as if its AI was drawn in with crayon and backwards R's.