I wasn't in the military, but I worked with the USAF and work with the USCG as an Auxiliarist. But even before my interactions with the military, I liked to put a good shine on my dress shoes, black and brown. I even did so for my hiking boots (and still do), but for those I use SnowSeal (basically beeswax) on all of the seams, which I melt into the stitching with a hair dryer, then I polish them well. It all adds to their waterproofing, plus it looks good. When they are muddy, I rinse them off with a hose, dry them and redo the treatment. I've even waxed my waxed-cotton jackets. It takes time, but I always take care of my equipment, even urban dress equipment.