The methods here are almost the same but we provide several of them for your advantage. So that you can choose the one very flexible to what you have and where you are.
Tip 1: Break the shells. Remove the bottom of the snail with the shell just a little part. Put removed snails in hot water for a while. Wash slime thoroughly with salt. Boil or fry till cooked. You may also boil it when cooking rice or other desired meals.
Tip 2: Put them inside water and boil for some minute (live or dead ones). Then remove the shell from the snail and wash with alum or lemon until pure and you can fry it with vegetable oil.
Tip 3: Pour it directly into a boiling water with the shell and allow it to cook for 10min. Pour into cold water and remove it 1 after the other using a sharp object like a pin or a fork by plugging it out. There after remove the physes and use lime orange to wash to remove every other physes.