I am having a very long and annoying time removing the old caulk from
my tub where it meets the tile wall. Somebody did a terrible job
recaulking, a while back. I tried repeatedly to deal with the mold
exteriorly with various mildewcides. Nothing worked, so I have now
grasped the nettle, and day by day, am chipping away at this train
wreck with various tools, mainly a razor blade in a straight holder.
Ghastly business!

QUESTION: Since I don't ever want to go through this again, I want to
clean/disinfect/whatever the area with the strongest and best
mildewcide on the market before I recaulk.

Everybody has their own favorites. Is there a concensus?

TIA