I've never once tried to scruff a mink. I can't say if it's good or bad, but my gut feeling is it's really not a good idea with mink. The people I've heard that tried scruffing found it made things worse, but I don't really know how or why they used scruffing. Most successful mink people I've talked to avoid using any physical punishment, and find a different type of punishment to discipline their mink. I've heard of people who use time outs, and I've recommended timeouts to one of my friends and had it work well, but I've actually never used time outs myself. I'm personally a hypocrite as I tell people to not use any physical punishment, but then end up doing it myself LOL. I guess I just don't trust most people with their wisdom and judgement in using physical punishment.
Physical punishment on a mink obtained as an adult only makes them fear, hate, or avoid you. It will also make them try to get you back in a sneaky way, like bite you when you aren't looking, then run and hide.
With babies I use my voice as a punishment and reward when needed, and try to avoid using any physical punishment until I really have to. I'm not recommending the physical punishment thing, just stating the truth that I do end up using it at times. My form of physical punishment is usually grabbing their head, and holding their mouth shut while looking at them so close it's almost nose to nose and saying harshly "NO!!! NO!!!!" I hold them for a moment like that and then put them down. You don't want to do that for too long, as the longer you do it the more angry they will get. I honestly can't tell if it helps, or just makes things worse, but that's what I do. I avoid the physical thing as much as possible, as more often than not it just makes them mad.
It's really best to find a none physical way to punish your mink, like time outs, or a harsh voice. Too much, or too rough of physical punishment will just get you bit, and make your mink hate you, so use any physical punishment with caution. I really think scruffing a mink will just get you bit and accomplish nothing, but that's only an opinion, as I've never dared to try it. A harsh voice, followed by lots of praise when they do something right is the best way to go. Here's a couple videos showing two different mink I've bottle raised, and how I reprimanded them when they started biting too hard.
This is Rocky when 6 weeks old, and how I get him to bite more gently...http://youtu.be/_qGEix-uZ58
Notice how I give him a harsh "NO!" then get him to play with a toy instead, and when he does I give him lots of praise.
This is a female mink named Inshta'pede several weeks older than Rocky was in the first video. It shows how I reprimand her for biting too hard, then verbally praise her when she is more gentle. You can skip to the 5:00 minute mark in the video if you want to see what I'm talking about.http://youtu.be/QRSLYYbvtng