Surface Sterilisation

I use 'Kalium(-potassium)permanganate' solution. I don't know the english name for it, but it's the stuff that comes in small crystals which make a very deep purple colour in water. It's very cheap and I can buy it at every pharmacy here. 

I usually make a nice pink solution and soak the plants for about 20 to 30 minutes. Didn't get rid of the snails, however, so the concentration was probably too low.