my last pin last week gave me a really bad soreness,my butt was so sore i could barely get out of bed the morning after..this is what happen,i wiped the pin area with alcohol,before the alcohol even evaporated(area was pretty soaked with alcohol) i pinned myself and it was kinda painful than the usual as the needle went in..im guessing from the alcohol..though i'm not sure if that's the reason why i had such a bad soreness/pain the next day or two..but still I will not be doing that again..