I do this all the time, and instead of drilling Seaglass, I make my
own. I take all my stained glass scraps, put them in a tumbler with a
handful of small pebbles, a cup or two of sand, a cup or two of
water, and if I'm in a hurry, some 600 grit from Kinglsey North. I
tumble for a day or two and then have Seaglass, frosted and rounded
edges. I also save colored wine bottles, slice them into glass
circles ( or glass ovals if its Matuse Rose) with my diamond saw, and
tumble them also.
I drill holes in them, hang them with beads on a metal ring and make
glass wind chimes. So far, even in strong winds, they don't break,
and sound like the phone ringing....
To drill the holes, use a piece of kids modeling clay, make a donut,
press it over where the hole will be, fill it with water and drill
slowly, occasionally raising the drill to remove the sludge. If you
press to hard, when you get to the back of the glass, it will break
and make a funnel shaped exit hole. To prevent this, use two pieces
of glass, and drill through the first into the second. It will
prevent the funnel shaped exit hole.
If you tumble after drilling, the edges of the drill hole will get
rounded and wont cut the string you use for hanging.
Love and God Bless