May I be so crass as to suggest Prop Speed or its new competitor, Prop Gold? You know, stuff that was designed to do just what you want???
It costs a bit more than antifouling paint
, but it works... fancy that!
We've cut the costs a bit by chatting up a marine service
provider that will sell us just enough to do our prop... costs about 30 AUD,lasts a couple of years. Oh... you don't have to be some sort of neurosurgeon to apply t he stuff... read the directions an follow them closely.