Wax on its own isn't very protective at all. I'd really suggest something physically stronger and more permanent.
Most people on here who've struggled with the DT final coat drying have swapped to using Tru-Oil. The only proviso with that being that its very slightly yellow, so on a blue finish it can make it look a bit green. Fine on all other colours.
I have got some, and use it on glossy necks if they ever feel too sticky. It's the main constituent of a lot of car waxes and is also edible, and used as a glossy coating on sweets/candy and some fruits such as lemons.
'Hard' here is relative term. It's a lot harder than say a beeswax finish, but soft compared to a nitro, poly, acrylic or Tru-Oil finish.