Have you tried dissolving the wax in natural turpentine? You’ll need to do in a bath of hot water, obviously, to avoid a fire. I find it soaks in more quickly. For a harder finish you can add a bit of carnauba wax.
I wonder if that would work for diy waxed canvas as well..
Previously I've found the process of rubbing solid wax and heating it afterwards to be quite labourintensive and quite difficult to achieve full and even saturation.
Have you tried dissolving the wax in natural turpentine? You’ll need to do in a bath of hot water, obviously, to avoid a fire. I find it soaks in more quickly. For a harder finish you can add a bit of carnauba wax.