Cleaning Mold From RTV In Shower Stall ?

Have you tried Chlorine bleach?

I would just go ahead and remove the RTV and replace with tub and tile caulk. Better to be done with it and not to have it come back.

Searcher

There is a hand tool that will remove the caulk without damaging the tiles. It's basically just a plastic V-shaped blade with a handle. You'll probably be done removing the caulk in less than 5 minutes. Check in HD or Lowes, or your local hardware store. Here's one:

Mix a 25% solution of liquid laundry bleach in cold water. Use a disposable spray bottle to spray it on the moldy areas and let it sit overnight. If the area is large, the chlorine smell will be strong so provide ventilation. Also, wear old clothes because of the obvious effect of strong bleach on clothing.

I've used this method numerous times in fiberglass showers and porcelain tubs and it'll clean the caulking, or tile grout for that matter. The chlorine in bleach will not only remove the black stain, it will kill the mold so that it won't come back so soon. It even penetrates silicone caulk slightly to get the mold organism that embeds itself in the surface. Eventually, it will come back and you'll have to reapply the bleach. Discard the spray bottle after you're done because if you try to save it for next time, the check valve in the spray head will probably be ruined and it won't spray.

Harry

theres both soap scum remover and mold remover in your local grocery store. kinda pricey at 3 bucks a bottle but it works great.

the soap scum i use all the time

the mold and mildew remover during the humid summer