CBH,
Ya, pack more new gland material over the old leaving a cut in the middle, don't break the bronze nut that could have been on it for years, don't inspect the shaft for corrosion, maybe drop some pieces around the shaft into the mud in the marina, lubricate the gland in the presence of water, work against the water pressure in a small area without the help of a friend on the other side of the hull, sleep very soundly 40 miles offshore, then when you take 20 minutes to pull the boat in a month, do it all over again because you really like to do repeated headstands in your bilge.