I had a friend like that. He would wrap a cloth bag around a can of spray deodorant and huff until he felt his lungs start locking up. Not a bright guy.
Anyway, how does anybody still huff compressed air? They put emetics into that stuff now. If you’re going to make the effort to build up a tolerance to that it would be a lot easier to just buy nitrous oxide from a kitchen supply shop.
My first job out of school was as a Juvenile Hall counselor. I had to deal with lots of glue sniffers. At some point there's not much you can do to help them since their brains have gone permanently by by.