Nobody thinks about shower door tracks until the doors barely slide or water starts leaking onto the bathroom floor. Soap scum, mold, and mineral deposits build up in those tracks faster than almost anywhere else in the house. The real problem is the weep holes -- tiny drain holes in the bottom track that let water flow back into the tub. When they clog, water overflows the track and hits the floor. The deep clean takes 20-30 minutes with stuff you already have under the sink. After that, a quick monthly wipe keeps it from coming back.