Why shouldn't I use Anti-bacterial ointments?

Well for starters read the package the stuff came in, right off a box of Fougera Bacitracin Zinc Ointment USP, "Warnings: for external use only. Do not use in eyes or apply over large areas of the body. In case of deep or puncture wounds, animal bites or serious burns consult a doctor. Stop use and consult a doctor if the condition persists or gets worse. do not use longer than 1 week unless directed by a doctor. Keep this and other drugs out of the reach of children. In case of accidental ingestion, seek professional assistance or contact a Poison Control Center immediately."

A piercing is a Deep Puncture Wound and the reason they want you to consult a doctor is that Bacitracin and other Anti-bacterial over the counter ointments are petrolatum based. The problem is this, the petrolatum blocks the flow of oxygen to the wound slowing down the bodies ability to produce new tissue. It blocks the wounds ability to discharge waste and debris from the wound. Since the petrolatum creates a film around the wound area that doesn't wash away for a few day, dirt, debris and pathogens collect in the wound area. So, OTC ointments slow healing, impede your bodies ability to remove harmful elements from the wound and increase the likelihood of contamination.

There is a misconception when it comes to antibacterial ointment. It doesn't actually kill the bacteria like Triclosan and other products. What they do do is reduces the ability of the bacteria to reproduce to give your body's natural immune system time to fight off the infection before it spreads. So, what is the point of using OTCs when you are already cleaning the wound with an antiseptic twice daily. Not only is it over medicating but also introducing another element that is known to cause problems.
For more info on healing a piercing go toAftercare Index.