It is cool but I assure you it's all pure coincidence. You'll notice that most of those don't sound much like what they are saying it does. The "message" is in the ear of the beholder, as everyone can find something that vaguely resembles something else in any random noise.

Listen to those without watching the subtitles and you'll quickly release that they are really stretching out on a limb for most of them.

However, messing with my 4-track tape deck years ago, I found that "dead short" sounds like "Oh, shit" ("Oh, shnit)when played backwards (or maybe it's the Devil!)