@Team Peroni
IMO, there are four factors (in addition to keeping calluses from building up too thick) that can greatly reduce your chances of developing a hand tear: hand strength, technique, conditioning and discretion.
Thank you for such an in-depth comprehensive explanation. A massive help. I am determined to master the art of the KB snatch as I feel it's such a big bang for your buck.
Hand tears come from overgripping the bell and holding the handle too far into the ball/palm of the hand rather than the fingers, especially when the handle is rotating in the grip. Friction enhancers such as chalk exacerbate the risk of hand tears.
Hand Strength:
The stronger you are, the more you can securely hook the handle in the fingers and maintain that kind of grip when fatigued. Also, the stronger you are, the less you need chalk. Not using chalk gives you a lot bigger margin for error. The increased friction with chalk gives a more secure grip, but will more harshly punish overgripping and tends to dry out and irritate the skin. You will probably find that not using chalk will slow your progress to bigger bells, since your hip power will progress faster than your ability to hold onto the bell. Personally, I really hate to use chalk and avoid it as much as possible, but do find it useful when transitioning to a larger bell, when conditions are more hot and humid, or I am doing a longer session that gets me sweating a lot, so I do end up using a light dusting of chalk most of the time.
IMO, hand strength for snatching is very specific to snatching, so supplemental grip training does not have a lot of transfer. I don't even find that heavy swings have as much carryover to snatching as just snatching, even if you are snatching a lighter bell.
Technique:
The better your technique, the more consistently you can keep the handle hooked in the fingers, and avoid gripping tightly when the handle is rotating. You also get a feel for when you need to grip more tightly and when you can relax. This not only reduces stress on the skin, but also minimizes fatigue so you can maintain good technique longer.
It can't be overstated how important technique is in avoiding hand tears. There are a million subtle ways to reduce and smooth out the force and friction on the hands, most of which would not be obviously visible to an observer. A lot of this is a feel you develop with a lot of experience and trial and error, more than something that can be easily communicated.
I've been snatching kettlebells since 2001 and I did tear up my hands earlier on. The best teacher is to do a lot of reps, experiment with subtle tweaks, pay attention to the occasional "happy accidents" where you stumble into unusually good reps, try to replicate them and refine over time.
(Skin) Conditioning:
Skin becomes conditioned through frequent and consistent practice so that the skin is tougher and less prone to tearing. It isn't just developing calluses, which can cause problems if they get too thick, but a general overall toughness, even where the skin is not obviously thick or rough. This can take months and years of consistent practice.
Discretion:
Discretion is the better part of valor when it comes to your hands. Cutting a set or session short if you feel a hot spot developing is much better than pushing through and getting a blister or tear that will affect your training until it heals. If your hands start feeling a little hot on a given day, that's a sign to stop for the day. Time to stop for the day does not mean "after I finish the last 5 sets I had planned to do."
With experience, you do get a feel for hotness that isn't critical and hotness that is, but still err on the side of caution. One of my favorite Dan John sayings is, "Train today like you are planning to set a personal record tomorrow. Then train the same way tomorrow." There's always another day, so the fact that your hands might be a limiting factor is not a problem; if it's a fact, then just accept it as such and work within it.
If you have to cut sessions short because of your hands on a regular basis, you are pushing the weight and/or volume too much for your current level of strength and technique.
Hope this helps.