Trifecta Crop Control worked for me, it is pricey and works for bud rot and WPM.
Botrytis is very serious and terminal (gray mold/rot), I have read nothing is effective against it, though some try H2O2 and water 50/50. An old timer told me to spray it with evaporated milk, and I would try it. What I read is destroy the plant, google it up and do some reading on it. I think I have a peach tree with this, so far nothing has fixed it, I will try evaporated milk on it in the spring and see what happens. If I kill it, well thats whats recommended anyway.