"they still have to use enough to turn rock hard carnauba into a liquid"
this is NOT true, the rock hard carnauba is first melted, the solvents only manage to keep it from re-hardening when liquified by heat. The fact that it takes melting the wax to make it usable should tell us that adding the solvents to the fully cured wax will have little or no impact, otherwise the production of the waxes could be done without heat. Make sense?
Also, the hardness of carnauba has been repeatedly compared to concrete - think about the way concrete is used...
Water is added to a mix, the water holds the particles in suspension, keeping the substance pliable and formable. After curing, the concrete hardens, but... pouring water on top of it will not cause it to go back into suspension.
Make sense?