It sounds like your doing fine. You will need to lightly sand whatever is left and prime with something to grip into what might be a dusty residue.
It also would be normal to ahve to do a bit of skim coating to get it smooth again- but if you prime with a primer/sealer and look at it with a light you will know.
It also would be normal to ahve to do a bit of skim coating to get it smooth again- but if you prime with a primer/sealer and look at it with a light you will know.