I have always done it the way the GMC book says. I would suppose the same applies to Chev. I couldn't get it all to fit in one picture with my phone camera. I had to make two pages out of one. I use a razor blade instead of a pocket knife.
I don't think an sealant will help. Either you get it in right or you don't. I cut them almost flush, and then pack them a little with a drift punch. I have never had a gusher, but they all weep a little.
