Several people have told me they use "penatine", it's a zinc-based diaper rash ointment for infants - really!!.... quite sticky and seems to stay on the prop, and does the job.... probably costs less too...
1984 Fast/Nicholson 345 "FastForward"
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)