Well alot of people will do a bleach solution dip using a 1 part bleach to 20 parts water, and you only want to dip them for :30 sconds to 1 minute depending on the size of the plant. After the bleach dip you want to quickly soak the plants into a bucket of regular water with a little extra dechlorinator for 10 minutes (away from the bleach water), and while they sit in the bucket of fresh water you want to wash your hands thoroughly to make sure they don't have any bleach on them. Then pull the plants out the bucket of fresh water and smell them, if you smell bleach, then continue to soak them in the fresh water for another 10 minutes, but if you don't smell bleach then they're good to go in the tank.