No drying, during the curing phase, Steven!
Actually the curing is drying and it is meant to happen. This video shows traditional curing and smoking of bacon and hams,
https://www.youtube.com/watch?v=S6UkXhHUTfM Around the 2 minute mark you see how the bellies and hams are laid on wood benches covered in salt with more salt being rubbed into them. The gentlemen in the video is using Morton's Sugar Cure and kosher salt. As you can see there is no attempt to bag or capture run off liquid. Any moisture extracted from the meat is allowed to drain away on the open wood bench. This would be the same affect of draining off accumulated moisture from the zip bag.
Our use of zip top bags is one of convenience not necessity. I often do large cuts of belly in a meat lug (tub), doing so leaves only a small portion of the bellies in direct contact with the run off liquid. There are no ill affects or one sided tasting food.
Modern bacon recipes make the point that when using zip bags, flip the bag everyday. I believe that is more to do with flavoring the meat than curing it. If you watch the entire video you learn that he used three steps, curing, flavoring (glazing) then cold smoking. By adding the syrup or brown sugar at the start of the cure we skip the flavoring step the old timers used.
We do rinse the cure then dry it in the fridge for at least 24 hours before smoking. I'm not sure if it is in this video or another of the same men I have watched but the old guy says, "After 7 or 8 days I wash it, (the meat) let it dry and smoke it".
