Wow, I have heard some crazy tales of how people treat gloves, either for breaking in purposes or general maintenance, but I don't think I've ever heard of someone using Sno Seal. Wow.
My own experience is that the most common cause of internal cracking in a glove is from perspiration and not wearing a batting glove on the glove hand. Seems to work for me.
Nokona used to have something on its website that said the six most important words to remember for breaking in a glove are "play catch ... play catch ... play catch." That has worked for me. Once you get it broken in some, the palm layers compress and the oil goo/glue will seep through a little and make that black spot about the size of a ball. I never add any oil or anything except a bit of conditioner on rare occasions.
Linking this back to shoe care, based on this thread I got a bottle of Bick 4 for - among other things - an old pair of Hanover PTB's in #8 shell. Once I got my rag wet, I started looking around for other things to condition. After giving my old Gladstone a good going over, I turned my attention to an old (cir. 1950's) Nokona J113 I found on ebay. It's really in pretty good shape but I've been reluctant to put anything on it in the way of conditioner. But, I rubbed in some Bick 4, let it soak it, and buffed it dry. Looks good with no darkening of the leather.