DC&MC wrote:
Dump a bunch of baking soda down hole and pour in vinegar. It'll foam like mad and cleans stuff up real good.
X2
I use this method all the time in the RV and at that house and it REALLY works. Breaks up soap scum and everything else. Be sure after the vinegar/baking soda foam up like a volcano you pour real hot water down the drain that helps wash away everything.
Do you have one of those glass octagon type showers that you have to step up to? A lot of times it leaks 'underneath' the pan and you might be smelling the mold from that.