Jason,
PMK stain shouldn't be affected by wash times. That said, since you shouldn't be using a wash-aid with PMK (that'll remove the stain!), you should be sure you're washing thoroughly. A 30-minute wash is what you need for film when not using a wash-aid, whatever washer you're using. Don't be fooled into thinking that aeration or agitation will reduce the wash times much; it's a function of dispersion, not activity. If you need to save water, you can alternate periods of flow with periods of simply soaking.
If you look at the sticky thread on film washing (there was a url link here which no longer exists) there are lots of good ideas on the subject.
Best,
Doremus