It can be difficult to get a finish to flow out and stick well to bare wood that has been waxed. Here’s how to proceed.
Wash off as much of the wax as possible with mineral spirits (paint thinner). You can use odorless mineral spirits if you want. Keep turning and changing your cloths or paper towels so you are lifting off and removing the wax and not just spreading it around.
I’ve seen cases where the wax is so hard that mineral spirits doesn’t dissolve it easily. For these instances, you can try naphtha, acetone or lacquer thinner, and you can scrub with steel wool or an abrasive pad.
If there are deep recesses, typical in turnings and carvings, use a stiff bristle brush, or even a soft brass-wire brush, together with one of the stronger solvents to help remove the wax and dirt from these areas. Try not to sand. You’ll round over the crispness of the turnings or carvings.
You can use soap-and-water to clean plain dirt in areas where it might exist. You need to get the wood as clean as possible.
Even so, you probably won’t get all the wax out of the wood’s pores, so after you have cleaned the wood as well as you can, brush or spray a first coat of shellac. The shellac will still bond well to wood with a little wax residue left. Be sure the shellac isn’t real old. Best if it was dissolved in alcohol (“manufactured”) within the last year or so.
Then you can brush or spray whatever finish you want. Be a little careful if you spray lacquer, however, to spray the first coat fairly thin so it doesn’t dissolve through the shellac and cause bonding problems.