Don't have a recipe, do know that some people use it. It's got way too low a melting point to be used straight. Should work great in any of the recipes that call for Crisco as a substitute. It'll raise the melting point a little and reduce the tackiness.
Fact is that most anything will work at midrange pistol velocities, say 1200 fps and under. Equal parts of parafin, soy wax, and lithium grease will surely work at that level and probably a good bit faster. 5 parts beeswax, 4 soywax, 1 vegetable oil would be a great blackpowder lube.
Your wife probably has some other great stuff in her candle supplies. Candles, soap, and bullet lube are very closely related. I've got a great source for beeswax it either you or she are interested. Email me for info.