I've got a bucket of cockles - freshly picked from the sea in Poole this evening. Not sure what to do with them now.
I've rinsed the shells as much as possible.
Mum suggested covering them in cold water and putting two tablespoons of flour into the water and mixing the cockles around so they get covered. (This cleans them out as they cockles eat it - ewwwwwww!) Leave overnight. Rinse well tomorrow. Then cover in cold water and boil.
Any other suggestions gratefully received.