I don't want to make assumptions, but I'm pretty sure our OP is describing a process I used to call "backloading". If I'm not mistaken he is describint a process of essentially removing the plunger from the syringe, pouring in crushed up Methadmphetamine into the barrel and then drawing water up into the syringe before mixing the contents into solution (by shaking or whatever).
I have known people who inject Methamphetamine to be unconcerned about the use of filters in the injection process. As far as the safety of this practice is concerned, I truly couldn't say. I know when I was injecting Heroin, nobody would ever do a shot without filtering through cotton. It was a pretty hard and fast rule.
When Methamphetamine started coming around, I'd see less and less people using filters of any kind and I've seen people backload like this also. Again, I wish I could comment on the actual safety of the practice, that is, not using filtration when injecting Meth. The best I can give you is that I'm not aware of people suffering complications from this practice that to me would imply it is a specifically dangerous practice.
If you wnat Uncle Keif's shot-from-the-hip bullshit answer? I feel Methamphetamine is often a very pure product compared to other street drugs. Any time I've ever seen Meth prepared for injection, there is literally nothing left either in the spoon, in the syringe or anywhere that would imply anything other than H20 had been present in the cooker.
When I would injecft Heroin, it seems there would almost always be some little bit of something, a brown residue, specks of bullshit left in the cooker after filtering and drawing up.
That's my opinion though. I think Meth makes a solution easily and there is not a hell of a lot to filter out.
