This topic was discussed at length a couple years back on the Eskrima Digest. You can search back issues by keyword at the following URL:
http://www.martialartsresource.com/filipino/filframe.htmMy take on this is that a lot of the rumors you hear about suction and such are akin to urban legends. I worked a lot of years as a chef; whenever some large chunk of meat needed to be taken apart I'd do a lot of the preliminary work with one fighting knife or the other. Never really encountered one of these problems.
Some would doubtless argue that a large chunk of dead cow doesn't compare well to a living human. Even if so, I'd argue good technique would prove effective regardless of medium. Perhaps if you were trying to withdraw a blade along the same axis of original thrust one of these difficulties could occur. But if you have a good reason to stick a blade into something in the first place, then you have a good reason to maximize the amount of damage done by the thrust.
In my kitchen experiments one of the best techniques I found once an initial thrust was made involved a snapping turn of the wrist--like quickly turning a doorknob--while throwing the elbow into the body and raising the arm in an uppercut-like motion. This resulted in a "U" shaped cut; I have a hard time believing a knife could remain grasped by suction or otherwise hung up after such a move.
For various reasons most blade oriented training spends a lot of time teaching students how to get a blade to target, but very little time working on what comes next. In real world encounters, however, I'd argue the latter point is the more important.
