Yes, I know edges should be wax free when sharpening but... We were having issues with the sharpener files becoming clogged. I initially tried boiling but that did little or nothing to remove wax buildup on the file. Instead, I held the files (with pliers) over a burner (gas stove) and scraped with a wire brush. This got the job done.
Oh, I should mention that the files get removed from the sharpener frame first. And don't grab those hot files with bare fingers.
In the future this will be done regularly and with a much better wire brush (this time all I had at hand was one of those brass toothbrush things). I'll use the wire brush I use for cleaning the files I use to sharpen my wood chopping and splitting tools.