does it help reduce scar tissue? and is it ok to use on a monroe piercing since its int he mouth

i read that emu oil helps with scar tissue no matter where on the body..

i use emu oil for my monroe because it gets dry from the soap i use to clean it. so yeah it's good to use even though its near the mouth area

yes it will be fine for a piercing around the mouth

ok the scar tissue is on the inside could i rub the emu oil on the inside of my mouth? 

 the simple act of massaging will help break down scar tissue.  if you want to use emu oil you can.  but it probably isn't necessary.

you could but it would taste nasty

Just a bit of a precaution: I would wait until the piercing is entirely healed before massaging it to remove scar tissue. If the fistula isn't completely healed, the act of massaging may actually serve to irritate. Judging by your posts, it's been about a month, but I'd consider waiting a little longer if you're uncertain. :)