What's the best way to disinfect aquarium rocks?

I usually fill a 5 gallon bicket or a 15 gallon tub depending the ammount of rock with water. Put the rock in there and ad a half cap of bleach into the water if its a five gallon bucket or full cap if its a larger amount or water, let it sit overnight and rinse the rock out the next day then let in sit in tap water without any chemicals for another day. This also works wonders for killing alge.

you can also boil them in water and vinegar. it's quicker.

no . . . many hobbyist use vinegar for various cleaning applications. you can boil with vinegar and water and then boil again with plain water, in order to remove the vinegar. after the boiling with water and vinegar, i would just rinse the rocks in water from your sink, but if you want to boil in plain water, to remove all traces of vinegar, so be it.

Dunno about the permanganate but I'm in the boil if it's small enough to put in a pot, or light bleach sollution and plenty of rinsing if it's too big, camp.
Rav