Well im not sure what you want to kill but hell to kill off worms and inverts u can all ways use an algaecide such as No More Algae. That pretty much cleaned up my worm and snail problem about 6 months ago.
My tank wasnt planted then though. I have read on here how to clean off plants using bleach, cold water, hot water, and soaps. You might want to check in on those.
But, if you want to do a full tear down. Take out the plants and creatures you do want. Add Bleach, either real hot, or real cold water, and scrub.
This is at least how I would think to do it based off what I have read on here.