Any suggestions on using something different that has been proven?
I use a number of leather boots for different tasks. For backcountry backpack hunting where I cover many miles and may pack in and out a heavy load, side-hilling, etc., I'm wearing Kenetrek Extremes for support. Bowhunting when covering lots of ground and hiking with a light pack and have no need for side-hilling with a heavy pack, etc., I'm wearing Redwing 914. Between those two ends, I wear several different leather boots for different chores, running in the $300 to $500 price range.
Things I've confirmed true to me with my use and experience:
A high end quality boot leather will have tight enough pores that they can be made waterproof to a durable degree, even without a waterproof bootie, using beeswax. This would be on the extreme end of hard use in very wet conditions.
Mink oil use does soften leather, and though I use it routinely on certain boots I own which are designed to be soft and comfortable, I would not use it on boots designed to give support with stiff leather, especially if the leather is dry tanned.
Nikwax works well on my light hiking boots, but it appears to me to work more like an invisible water-repellent finish (DWR) that is not near as "durable" as other applications when exposed to hard and rough use.
For hard use wearing stiffer support backpack boots, such as my Kenetreks, especially if the boot has a rubber rand, I've had great results using their Kenetrek Boot Wax. Even with Thinsulation and a waterproof membrane bootie, this boot wax has worked top shelf for most anything I've thrown its way. Not to the degree of raw waterproof as straight beeswax, but a great balance of protection without making the boots act like a non-breathable sweat box. In comparison to something along the lines of Montana Pitch Blend, I find the Kenetrek Boot Wax to be superior when it comes to a treatment for these stiffer boots, which you'd want to stay stiff for needed support.
When it comes to softer leather boots with a membrane bootie, I'll use either the mink oil, or something along the lines of the Pitch Blend if I need an added level of waterproofing. Hard working boots, such as loggers, needing an extra heavy level of protection, but not to the degree of straight beeswax, I'll generally use something like Obenauf's Heavy Duty LP.
I do not have cold feet and generally do not need much if any boot insulation. Something suggested to me many years ago by AJ Brooks when the trend in mountain boots were going toward membrane booties, was to get boots with some insulation. The lower levels of Thinsulate insulation does not make your feet too hot, but better maintains your feet at a constant temperature, even when in warmer conditions. The added benefit with this insulation is that it speeds the drying of moisture from inside your boot, similar to how stuffing your boots with dry newsprint overnight helps wick out moisture. I have repeatedly proven their advice to be true and correct with my experiences. So as a result and example, my Kenetrek Extremes having a membrane and Thinsulate insulation. When combined with their boot wax and good socks, my feet stay comfortable and dry, without any degrading of the boot leather, to include while backpack hunting many miles over numerous days. One trip using my current pair, I covered 21 miles in three days in rugged country with lots of rain, side-hilling, scree slopes, etc., and the wax held up well, my boots managed the moisture, my feet stayed dry, and the leather maintained support and did not wet out. I am not confident an application of Nikwax would have held up like the "greased" leather.
Best of luck
