That's not a snot rocket, that's just gross. Proper snot rocket technique can be seen here, in some random video about Brett Favre:


Yeah, I don't know either. Anyway, it's quick and not too messy, although a pair of ski or snowboard gloves are nice to have for when you don't get a totally clean discharge (said gloves usually come with a swatch of soft, brushed fabric on the thumb for the purpose of wiping your nose; just don't mix up thumbs if they also have a goggle scraper on the other thumb).

Rockets are handy, but I usually just swallow snot until it reaches critical mass in the throat, then loogie. Almost zero chance of self-contamination (as long as you don't loog into the wind), plus it doubles as an especially nasty "**** you" to cars that aren't respecting my personal space or right of way.