My trick is to use my favorite scented votive candle. needle, cut and knot the thread. Pull the thread across the candle wax and then pull the thread under a warm iron. The iron removes any excess wax and the thread feels starched. my favorite scented candle is Citrus and Sage by Yankee Candle and it smells so good while hand sewing. One candle has lasted for a few years.
I tried the beeswax that comes in the little round disk. It wasn't very nice and just crumbled apart.