I live in a two story townhome with two bathrooms upstairs that have fiberglass shower tubs. I don't know much about plumbing, but have lived in this house for years with no problems. Only now both shower drains are giving off a nasty odor. In trying to fix the problem with vinegar and baking soda and scrubbing down the slime from the pvc pipe, I accidentally dropped the overflow plate screw down the drain and I believe it's now in the P trap?! I tried a magnetic telescope thing but the screw is not magnetic. Should I call in a plumber or can I retrieve the screw myself using some other means? Any advice would be greatly appreciated!