Where do u live? Even for ebay you can't get it? I hope I can... I dont know how its the method of exit bag
I'm living in nz, and because of biosecurity they are very strict on customs.
So unless I find someone that sell it under the table, it's a restricted to business or labs only :(
Exit bag is have a mask or a plastic bag on your head with an inert gas (helium or nitrogen for example) that is diffused inside. If you can deal with the bag on your head, it is painless and quick death, because your die from the lack of oxygen but your body to go in panick attack because you can still breath but just no oxygen.
You have few thread about it on the forum, It I'd just did a quick summary