MTB gets all kinds of crap on chains. Oiled chain drowned in "forest grit water" sounds very bad. With waxed you pressure wash, and get few more rides from it, until melting again.
Pita is to remove factory grease, all else is cake.
you may try moto chain sprays, but road bikes have hi speeds so the spray is very tacky....
look for offroad...
it has solvents so you flush and lube at same time.
i´m fully on wax, goodbye oil...