I'm a bit circumspect in my use of wax willo - waxes ain't waxes, in my experience there can be dramatic differences. I prefer to use epoxy.
Wax does have a couple of advantages over epoxy. One is the extremely fast hardening time, as soon as it's cooled you can start. Another is the fact that you can re-position something after it's dopped if necessary, simply by warming the stick up.
However, they are nowhere near as strong and I have knocked wax-dopped stones off the dop with a fairly light bump. I have accidentally banged epoxy-dopped stones much harder with no effect.
When I do use wax - only on things of little value or that don't belong to someone else - I use the brown wax I bought when I started cabbing. It's far superior to the black faceting wax I bought.
I'm not saying that it's superior to all black wax, perhaps I just got a bad or old batch. I have found this particular black wax to be quite brittle (the brown stuff is tougher), to soften and melt at a lower temperature contrary to claims of high-temp wax, and to be so soluble in alcohol that simply waving the stick over the mouth of an open bottle of metho results in the stick instantly becoming sticky and gummy just from the fumes. The brown wax by contrast seems very reluctant to begin dissolving in alcohol and even after 24 hours soaking it's still firmly attached - it's pretty clear that there is a significant difference between the chemistry of the two, or at least very different proportions of the same ingredients, leading to one being not too bad to use as long as you're careful while the other is about as useless as tits on a bull.