I have spent a lot of time running a bar of wax over my Belstaff jacket. No longer, now I use spray on Nikwax.
Every now and then my waxed cotton jacket needs a touch up. Nikwax is about 1000x easier to use than a solid or cream wax. You liberally spray this on, rub it in and let it dry. I find it has a pleasant, not noxious scent.
There are two colors: green and neutral. Make sure you check the label, although green will work fine on black. It is a very light tint and won't show through, at least on my ancient jacket.
California's recent rains show this stuff not only goes on easy, but works well.
Nikwax Wax Cotton Proof via Amazon