No one knows for sure, but apparently there was an experiment by a foil manufacturer after reports of problems with people smoking H off of foil. They said, at those temps (higher than that of a bowl), it doesn't cause brain damage, however I don't know for sure. And I don't think anyone else does. I've done this plenty as a teenager but I'd recommend that you try to avoid it
Edit: sorry thought it was a grass bowl. If for any powder, should be the same as chasing the dragon... The jury is out on that (and probably won't return for a while).
I will share a DMT smoking tip that helped me but I don't know if this is any more or less damaging (I think less). If you get some of that kitchen mesh stuff, made out of metal, you can put a bit into a bowl, and then melt DMT (or in your case, whatever benzo) onto it, and then when it's stuck to the mesh, hit one more time and it should get all the powder. As long as you don't BURN the metal this is probably less harmful than foil. But before you do it, research it to make sure
I also agreed that smoking benzos won't be much better than eating them, since most have a 90% oral bioavailability or so. There's really no point in doing anything else. I guess some lams are better iv from what I read but that's mostly midazolam