I've never had the 50% laundry bleach + 50% water fail unless someone had
put a sealer on after the mold had already begun to form. Spray it on at
let it soak into the grout and leave it alone for several days. If you
don't get all of it the first time, apply again. Bleach will kill the mold
and it won't come back for quite a while. The same concoction even kills
and decolorizes mold on caulks for me, even silicone caulk. If the grout
has been sealed and the mold is under the sealer, the sealer will have to be
removed so that the bleach can get to the mold underneath.

wrote in message
oups.com...
What's the best way to remove the black mildew stains from the grout &
caulking of a tile shower area? Tried bleach, helped but not entirely.
Stores only seem to carry products for soap scum & hard water (lime
away, CLR, etc).

TIA

Rick