One good thing I have read is to use a 5% bleach wash for your plants.
I use 100ml of bleach into 2litres of water.
And I allow my plants upto 3minutes soaking time in this solution. Then I hand rinse them under the tap to remove any left over slimy eggs etc then I dunk them into dechlorinated water.
Then add them into your tank.
I've had an outbreak of Planaria, Copepods and a single snail from plants I didn't wash prior to adding them into my tank.