I was thumbing, or rather scrolling, through the Peterson catalogue and saw that a few of the pipes I have from Peterson are able to use 9mm filters. I was curious as to what kind works best with them? I know some guys don't like filters at all, but I'm thinking filters might help to curb my ginigivitis irritation when I smoke. So once again any advice on what filters work best with Peterson Aran series, I have a B5 and an 05, would be greatly appreciated.