It is tough to get a load-out that is efficient in doing this at a low level, however it is worth the time to farm the Corrupts at Bathery Row.
I leveled 10 times (levels 20 - 30) in two days farming the code, and trading it for experience with Fumigator. This was also only playing part time, and on a team for about half of it with people at or above my level.
