If you really want to get medieval with your cleaning, a 10% bleach solution will kill the bad (and good) stuff back into the dark ages.

You just have to rinse and rinse and rinse to get the bleach out afterwards. Rinse until you're sure it's clean, then rinse again just to be safe.

Hydrogen peroxide works very well and is easier to clean up after than bleach, but bleach kills faster and more completely. If you have a virus or something hit your plants, it's better to be safe than sorry. Nuke the system with bleach, make sure everything is good and dead, and then clean up and start over.

H2O2 will probably get it all, but I don't want to worry about "probably" after something like that. For most situations though, H2O2 will be fine.