I buy rusty cast iron for CHEAP at the Goodwill, brand new cast iron can be spendy! Great way to restore them. How To Clean and Season Old, Rusty Cast Iron Skillets.using salt and a potato. See also commenter about putting a rusty skillet in the fire.
Clean glass showers using lemon dusting spray (like Lemon Pledge).gets rid of soap scum & you won't have to clean it again for a long time, since the spray repels water! Many comments on the original post say it totally works! It's worth a try