How to quickly prepare snails? How to quickly prepare fresh snails?

I've heard snails must be soaked in salted water for a few hours in order to remove the mucus but a friend of mine suggested that the ones in shells can be simply thrown into the hot ash and after a dozen of minutes they can be taken off the shell and eaten. 

Was he right? What is the fastest way to prepare snail for eating? I mean, fastest way to prepare them so, that they would be safe food (killed parasites etc.)
The fastest way would be simply to boil them in salted water for a few minutes. 

Throwing them on ashes (a barbecue?) would do the trick also, but I guess you might want to leave them there for more than a few minutes to ensure they were cooked throughout, and theres a bigger danger they'd overcook.