we have an inside stone wall (10' x 12') that needs to be pressure washed, but since it's inside don't know how best to clean it. The boys call it our rock climbing wall since the stones jut out, with no two stones being similar in their fushness with the wall. The wall is about 25 years old and don't think it's ever been cleaned - dirt, fungus, mold, etc. I've tried using straight bleach and brushing the stones, without much success (makes a major mess of water & mud) - don't really mind that if it was getting it clean, but it's not - any suggestions on how to pressure wash inside a home or something comparable to it?