Most people have never thought of seaming clams on the BBQ grill; the process usually only takes between 5 and 10 minutes or till you see your clams began to open. When completely opened, you can start removing them carefully to a large bowl, being careful not to remove the clam juices from the shells. With Clams, make sure they are open wide, but Mussels, on the other hand, will not open nearly as wide.
Take the barbecue itself - if it's seen better days then maybe it's due for an upgrade? Do you want the precision, efficiency and convenience of a gas barbecue or would you prefer the hands-on theater of a traditional charcoal-burner? Gas can be a real time-saver, assuming you remember to check the level of the gas bottle and don't have to make a dash to the local garden center to re-stock in the middle of the party.