I'm just wondering why. Not even nurses use them anymore. It's a dead practice.
What are you talking about!?!? Cleaning the skin is always the first step before doing a venipuncture, or especially an IM injection. In most places, unless it is an absolute life critical emergency, iodine swabbing is used before insertion of an IV. The second choice is alcohol, which is standard procedure for very sort term venipuncture, like blood draws, or when doing IM injections. You rarely have to worry about infection once something reaches your blood stream, as it contains quite a concentration of active immunoresponsive cells. It's the path from the surface of your skin to the vein, or in our cases, the path from the skin all the way to and including the muscle that is much more prone to infection.
The couple of studies that I was able to find discussing that skin prep with IPA or iodine was unnecessary only addressed the issue of preventing the own patients bacterial flora from becoming introduced subcutaneously or intramuscularly. The skin was always clean with at least soap and water. Given that fact that most of us have a relatively low native concentration of staph. Aureus, this is a plausable method of keeping the skin clean enough. However, the more dangerous infections are not from native dermal bacterial flora, they are from out contamination from the outside environment. The prevention of infection from other environmental bacteria and endospores was not addressed. This sidestepping of the real issue here makes these studies dubious at best, and downright dangerously wrong at worst.
tldr,
Swabbing absolutely does not make anything worse, and can only improve your chances of not getting an infection, It only takes a couple seconds, and costs next to nothing. Not swabbing my work out fine for you 999,999 times, but is it worth that one time something does go wrong to not swab.
