My basement walls were painted before I purchased my home. In some areas the paint is peeling up and there is efflorescence behind the bubbles. We had problems with water when we first moved in, but since we replaced the sump pump we haven't had any new flooding. I want to remove the paint and clean the efflorescence before coating the cinder blocks with a masonry waterproofer. Even though I think the moisture problems are solved, this would give me added piece of mind. What is the best way to prepare the walls? Thank you.