Here are some more thoughts on whole rubber boot thing.
I stopped using normal commercial preparations on my leather boots about 10 years ago. I used to be a Sno-Seal addict. Then somebody suggested beeswax. I went out on Ebay and found a lifetime supply for about $8. One treatment lasts 5-10 years. Besides doing an excellent job of waterproofing, it also smell-proofs the leather as well. If anything, the beeswax seems to pick up whatever I'm walking through. So if I'm walking out to my stand, the beeswax would pick up the grass and brush and leaf detritus.
When folks talk about rubber boots being scentproof, I would have them stick their noses down onto their boots. When I do, I smell Naptha-- a solvent used in the manufacture of the boot. My LaCrosse boots finally died after 25 years of faithful service this past winter. If you stick your nose up to those boots, you can still smell Naptha. I've never been able to figure out how somehow deer can supposedly smell everything with uncanny sensitivity, but they don't smell Naptha.
Lastly, there is one thing you probably can't take out of the equation, and that is what your boot is doing when it interfaces with the ground. As you walk, everything underneath gets crushed, squeezed, stirred , etc. You have to figure that the deer, if they can smell the passing waft of leather, must be able to smell this. I don't know of a way to counter this. I'm dead sure this nothing out there commercially available to cure it. My point is that you have all energy being thrown at making yourself scent-free and here you are creating scent just by the fact that you're walking on the ground. It makes me wonder if we're not just wasting our time.