Many aquarists worry about introducing algae and snails to their planted tanks, and sometimes people use a dip solution to burn off algae and snails. Depending on how robust the plant is, dipping them can be damaging.
I don't usually dip my plants at all; I usually just rinse them under running water. I find that most pond snails do not harm healthy plants, so I do not worry about having snails in my tank. Buying tissue culture plants avoid snails and algae problems entirely as they come sterile.
However, if you want to try dipping plants these are a couple of dip solutions:
The Hydrogen Peroxide 3% concentration is what is usually sold in drug stores.
Spray H2O2 onto plants directly.
Leave on for about 20 seconds then wash off.
Add 10ml of H2O2 to a gallon (3.7L) bucket
Let plants sit for 10 minutes, then rinse off.
Many aquarists use a 5% bleach concentration (3-6% is what is usually sold as household bleach) The steps:
Mix bleach with water in a 1 part bleach 20 parts water ratio.
Dip delicate stems for not more than 20 seconds
Tough plants like anubias can be diped up to a minute
Rinse off plants in water then soak in water with dechlorinator before planting