Aran pipes are not system pipes. That being said, many Petersons have a smaller moisture trap. Depending on the shape, yours may have one too.
On my non-System pipes, I run a pipe cleaner through the stem after each smoke. As far as it goes. Sometimes they get stuck in the moisture trap, sometimes I can wiggle one all the way to the bowl. Every half dozen smokes or so, I let it cool completely, take it apart, use a Q-Tip to clean out the moisture trap, brush stem and shank real well. With my rotation now, that comes out to about once a week or so.
Hope this helps.