Isn't Las Vegas in the desert? Would that not be considered "extremely dry" ? I use a Venta here in Michigan during the winter as my boiler severely dries out my home, and the winter air does not contain enough moisture to help. Many older furniture factories have steam misters to help add moisture carefully.
As for "sealing" to prevent transmigration of moisture- doesn't work and never will. Furniture making would be 10x easier if that were the case. Sealing only slows down the process- a lot, I admit - but nature seeks equilibrium. Lemon oil on the other hand, is mainly solvent with a little oil- a nice penetrating "cleaner" offering little protection. Wax will not keep moisture in/out, but clogs the micro pores/cracks a bit and ads a slippery protective coating. Both beneficial for longevity of any piece of fine woodwork. You might try asking a known skilled furniture maker in the vegas area, they will know. For the record, wax won't hurt anything. If you don't like it, lemon oil will probably take it right off ;).
Oh BTW, FWIW I've seen veneer over mdf crack due to severe dryness. Higher quality items will have a layer or two of "cross banding" (veneer with grain rotated 90 degrees) seldom seen in audio products. Really though, if your home is very dry you might look into some form of humidification. Your sinuses will thank you as well.
