About the boots that wouldn't seal:
In the old days, everyone got top grain leather boots, because the water resistance is in the top grain. Now, your see split leather everywhere, and some of it is so poor, there is no treatment that will work. Don't mind it on my Nevados, because I use them only for day hikes and walks in dry weather, and they are so comfortable and so cheap.
Sounds as if most have forgotten the old issue of Backpacker where they tested all the boot treatments and created quite a stir, a furor actually if you consider the letter they got from Nikwax.
While Tectron has its uses, mine is another vote for Limmer boot grease, limmercustomboot.com, because they know leather best, and it is designed to both preserve the leather and keep the water out.
Sam Farrington, Chocorua NH