Processing paper in drums

I plan to start doing a little contact printing (I've done trays since I was 13) with the Simma drums and roller. I've read a little on APUG but I am left with one doubt.
After the [developer-stop-fix-hypo-wash] run, is the drum clean enough to do another run? and how long (or short actually) can the wash be?
I am concerned about contamination.

I would like to use a Paterson washing tray after the drum, so the shorter the wash in the drum the better.

oh, and using fiber paper...