I always throw them on the grill drink a beer and wait for them to pop open then give them another minute or so. You dont want to leave them on to long or they will dry up and get chewy. My grandfather used to have big parties in his backyard and would have several beds of coals going with a piece of sheet metal over them and he would put the oysters on the metal and then put a big piece of wet burlap on them to help steam them I havent tried it that way yet but one day I will.
I would like to try to make Blackened Oysters, basically a butter sauce with blackening seasoning. Throw them on the grill for a bit for a little smoke flavor. I have only run across this type of blackened oyster and it was at a SC restaurant I frequented back in the 90s. They were freakin' amazing.
I had some good results with clams on my charcoal grill. I used hardwood charcoal and a mix of wood chips. I laid the clams on the grill so that the juices would not leak out. Unfortunately, I overcooked them (about 20 minutes, I think) and they were very chewy... but they still tasted wonderful! It was my first and only attempt, and I was still pleased that I was able to get this to somewhat work. Next time, I'll try for a sweeter smoke flavor and a shorter cooking time.
BobBQ is my brother. Hmmm, I don't recall the invite to that cookout. He would have needed more clams than that. We are on the North Shore. A little north west of Glostah.