People have used Potassium Permanganate dips for plants to remove pests/snails (algae too?), but it WILL damage plants in too high of a concentration. And most likely the concentration needed to properly disinfect the tank will surely be strong enough to kill plants practically instantly. Everything living, fish, plants, inverts, even beneficial bacteria should be kept away from the Potassium Permanganate at those concentrations. No way around removing the livestock that I am aware of, no matter what sanitizer/disinfectant is used (bleach).
Bump: Since the driftwood is very porous and can hold in moisture/liquid/chemicals, I would use bleach since the chlorine can be released pretty easily. I don't know too much about Potassium Permangante so I don't know how hard/easy it is to get out of the wood to be safe to reuse.
For the driftwood I know using bleach will sanitize it and after you sterilize it with bleach, you can just rinse off the driftwood well and leave it out to dry. Would recommend not putting it back in the tank until you no longer smell the bleach/chlorine as it can be harmful to the fish. You can also use a dechlorinator liquid (Seachem Prime) to take care of the chlorine. You could probably boil it too just to be extra sure.