the commin aquarium "pest" snails - pond snails? bladder snails, ramshorn snails and trumpet snails do not eat plants. as far as I know, some types of mystery snails and rabbit snails will eat plants. If you dont mind harmless snails I would recommend to keep them around. especially since they contribute to a healthy planted tank system. :)
As for the plants, you can keep them alove by letting them float in a jar/lunch box/ large container of tank water. make sure all the leaves are submerged and the cobtainer is in a well lit position. A window sill that does not recieve direct sunlight is good for this.
Keep in mind that PP stains stuff and is a strong oxidiser, it will give you spotty brown fingers easily :P use gloves!