Dowse with a pendulum, lying down, see what kind of energy you pick up first. It may feel like a bumpy irregular mini cyclone or feel very slow and stagnant if there’s an energy problem there.
Once you have a feel for it, use a crystal point, or your left index & middle fingers, and flick the gunk out like collecting then flicking cotton candy (bit more about that here: Tutorial : Tool-Free Magick Using Your Hands).
When you flick, visualise it burning up in the air, and dispersing.