meh

Those bottles wouldn't be efficient as a means of vaporizing. There is way too much surface area for the dmt to condense and recrystallize onto as well as having too much space inside the bottle to make the vapor concentrated enough to hold in with one or a couple of draws. Try looking for a glass single serve cocktail bottle such as Hennessy or Courvoisier. They will be much more effective for what you're looking to achieve.

fsd

By no means is unusable. It's just far from efficient and would result in a lot of material condensing on the glass while trying to use it. Getting a good technique down would be a hassle as well. Back to the original question...Are these good for vaporizing? No, but they're not completely useless. A 50ml bottle is what most seek out when building a machine.