The circular oscillating blades do a good job in plaster too. A few years ago we used a circular saw to cut a channel in plaster. Even though we constructed a tent there was dust everywhere and we looked like snowmen afterward. A few weeks ago we cut a similar channel with the oscillating tool, higher end vacuum cleaner closely chasing the blade, and no tent. Dust was not a problem. It is a good idea to wear hearing protection.

By the way the oscillating tool and straight blades do a good job cutting round holes in a plaster on metal lath ceiling. We used the diamond grit blades to get through the plaster and tungsten blades to cut the lath. Here we did use a tent and vacuum cleaner. We had excellent control over dust. The holes were nearly perfect.