I got mine done with a gun, no problems at all? I was also given some healing solution to apply every day.
Guns cannot be cleaned properly never mind sterilised. When one is used on you, it has a smattering of the skin cells, plasma, blood and more of EVERY person that it has been used on on it...
They also don't 'pierce' the flesh; they basically force a blunt bit of metal through your ear...And as they force it through your ear, it drags in all that plasma, blood and so on into a fresh wound in your skin...
*n