I've used mink oil in the past. Doesn't last forever, but reapplication every month works.
I'm with Shadow. Get some boots with Gore-Tex and be done with it. I've got some Redhead boots with Gore-Tex and 700 grams of thinsulate that are 5 years old, and have been treated with nothing. Tuesday, I walked through ankle deep water and mud for most of the day on an upland bird hunt walking many miles. My feet never got wet or cold. Same boots I used in New Mexico on an elk hunt last month walking in 8" snow all day at 8000 ft + with sub zero temps in the morning. Paired with some Marino wool socks, its unbeatable.
Spend some money and quit using work boots for winter footwear. The cost of waterproofing them over the years will be more than buying Gore-Tex and being done with it.
I'm with Shadow. Get some boots with Gore-Tex and be done with it. I've got some Redhead boots with Gore-Tex and 700 grams of thinsulate that are 5 years old, and have been treated with nothing. Tuesday, I walked through ankle deep water and mud for most of the day on an upland bird hunt walking many miles. My feet never got wet or cold. Same boots I used in New Mexico on an elk hunt last month walking in 8" snow all day at 8000 ft + with sub zero temps in the morning. Paired with some Marino wool socks, its unbeatable.
Spend some money and quit using work boots for winter footwear. The cost of waterproofing them over the years will be more than buying Gore-Tex and being done with it.