hmm..not that I've done this but could be that if you had a processor with some soft rollers in a tank, that would work for sistan, if the hard rollers were too much? I dunno....I remember reading an article about a lab in an archive that used a colex, I think, that was modified for toning, but this was being used for sheet film processing. I'm fairly sure it was dip & dunk as well.
it could be that you could go straight from the fix into the selenium then do your wash. I guess it depends on whether you have enough carryover fix from the previous tank, to forgo any stains. If the exit rollers are doing a good job though, then I guess you do need to do a quick wash. Probably 30 seconds or so would do for b/w. I pretty much shut off the dryer on the 2150 I use at work, and take that damp print and selenium tone it outside in a sink. It only gets a 20 second wash if that, in the machine. if you could do it straight after the fix, then maybe you could swap out the hard rollers with some soft ones to leave enough residual fix on the print so the toner doesn't stain....
The Printo though--I use one of these as well--seems like you could just remove the top roller from the exit part of the rack and the prints would still come out, but the chemistry would be left on them....might work for the sistan if it needs to be sopping wet.