Removing a wax finish from a wood countertop, in preparation for tung oil
Wax is pretty hard to remove, everyone seems to agree about that, then everyone disagrees about the best way.  Here is ONE way.  

You can use a solvent, rags, and elbow grease to remove wax.  When you apply the solvent to the wax, you get a liquid with wax dissolved in it, and when you wipe it the mix is absorbed by the rag, and thus removed.  With enough passes of solvent and rag you carry away most of the wax.  

For the solvent usually mineral spirits to get off as much as possible, and maybe denatured alcohol for a last pass.  (The alcohol will remove the mineral spirits as well.)  

For the rags, try fine steel wool or scotch pads for the first pass, then paper towels.  Use a lot of paper towels.  If the paper towel is dirty it's no longer removing wax it's just moving it around.  

I don't recommend using a heat gun, to me that just melts the wax deeper into the wood, but it does make sense to keep the ambient temperature in the room on the warm side and keep the solvents at room temperature, not out in a cold garage or something.  

When you think you've removed the wax, let that last pass of alcohol dry then spray the surface with water to test.  If the water beads up, try to remove more wax.  (Note that some naturally oily woods may bead up even with the oil removed so this isn't a perfect test.)