Injecting - Getting a Double Rush

[dyingtomorrow]

Synopsis: SWIM shot up with a dude who was talking about a particular way to get a double rush, and was surprised SWIM didn't do it or know about it, which weirded SWIM out since he didn't think there was much about H he hadn't heard at this point.
Story: So, SWIM was wandering around in the ghetto fucked up out of his mind last Thursday, but was fortunate enough to remember one thing: bumping into this young thug who asked him if he needed blowz ("naaawwww"), then told him this was their dope spot, and to come back Saturday at 10:00 for a pass out.

For those who don't know, a pass out is where a bunch of people, mostly bums, go to get a free bag of heroin (or maybe 2 if you've been shopping at the spot for years), which is distributed by the people who run a dope spot to let people sample their shit, maybe if it's a new batch and is good, maybe if business is slow, etc.

So SWIM went back today, and was hanging out at the nearest L (elevated subway that runs over the streets, as we say in Chicago) and started talking to this bum to find out if the pass out is on. Side note - one can always talk to bums to find out anything that's going on somewhere, or to get anything, it's a good thing to get in the habit of doing. SWIM ends up going with him and ask him if there is a safe spot to shoot up at around the area after we get our bag.

Double Rush Part: We go behind this building, and he asks SWIM if he does something which he can't remember the name of, like "flooding" or something like that. Basically he says that you get a double rush if you draw, let the blood in, shoot like half, then draw again and let the blood fill in some more, then push again and finish it off. There might have been more to it, but that's what SWIM remembers.

Anyone heard of this?

SWIM could maybe see it working if you were shooting a large amount that you know was going to get you fucked up. Like a "treat" amount, e.g. when SWIM shoots 2 bags at once instead of his regular 1 bag. SWIM's philosophy has always been that it's best to blast as much as you can as quickly, for the best rush. SWIM was going to try this next time he gets a good amount of heroin, but if anyone has done anything like this or heard of it SWIM for one would like to know.