abating small patches of joint compound (or faux plaster)
On my plaster wall from which I have abated paint I have a few patches of what seems to be either joint compound because that's what I would imagine someone would most likely use for that application OR faux plaster because the texture feels like it. I also think the latter is possible because they are just bumps, i.e not used to level the surface, and actually what's left of the whole wall being covered with that stuff. The plaster is over brick, the house is 100+ yrs old, hence the antique material.
I would like to scrape off the remaining few patches but they are pretty hard. I think it could be done with a large scraper that has a ball handle for the second hand to apply more driving force but I was thinking there could be a more elegant, power intensive way to soften the material and scrape it off more easily.
Does anybody know of a solution that, if applied over this (which is still not clear to me what it really is but pictures are attached) might soften it? Yes, I thought about sanding but the layers are to thick -- and hard.