I do not believe there really is a waterproof leather boot, sooner or later if submerged they all will end up leaking some.
I know russells are not waterproof, though I have had good luck with Gortex lined russells keeping my feet dry.
In terms of best compound to finish with I have been happy with Obenauf's Heavy Duty LP Leather Preservative. Earlier comments on silicone based products are correct, avoid them.
I have used Sno Seal in the paste and been happy with it as well.
I am probably a little overboard on boot care as it is the second thing I do after I get home. Order of march is: Dog, Boots, Bird, Gun, then other stuff. I clean and touch up my boots after about every hunt.
You can go to the Russell Moccason website for their description on proper leather care.
http://www.russellmoccasin.com/leather_care.html On the subject of Rubber Boots there are high end rubber boots available that have the proper support construction. At the low end there are neoprene lined ones (I have a pair orvis sold me that I wear now and then) and I have seen the leather lined Chameau, but never could get up the nerve to spend that much on a rubber boot I might only wear three times a year. If you are in water a great deal then a high end rubber boot maybe a solution. If leather only is your view, go with a gortex lined boot.
