Do not fuck a vacuum cleaner
I will never forget my high school health class. We had an assignment where every week we would have to bring in a newspaper article relating to an issue of health. One kid who was in another class brought in an article that was of such importance that the teacher felt the need to share it with all of her classes.
Apparently this guy was feeling a little lonely and decided to go with a vacuum cleaner blowjob. As it turns out, some vacuums have little blades inside the hose. When the vacuum is turned on, the blades rotate, creating air flow, and therefore suction. When the man inserted his penis, the blades relieved him of the top several inches of his manhood. Ever since hearing this I have been of the opinion that it is almost certaintly a bad idea to go for a vacuum cleaner blowjob.
This blog should serve as fair warning to lankganglia and others.