I've done it. You should be careful. The problem is that the black wax really sinks in quickly to the shoes -- unless it is really viscous, you'll find that where you initially put the wax will get more dark than the places to which you spread the wax. Cream would be less risky on this score, and I've mixed navy blue, brown, and red cream together for a nice look. However, if you go with wax, a good thing is to apply it in small amounts to the toe and the seam areas (basically anywhere where antiquing is easy and natural to apply). Err, maybe not a "good thing," but certainly something that won't be at all ruinous to the shoe and will give it a nice touch. I'd try Meltonian cream if I were you.