Legally they can’t call it honey anymore if they do that. A lot of it was done by large commercial operations to thin it, and keep it from crystallizing on the shelf. Mostly imported honey from Mexico. It is very similar to what Aunt jamima and Log Cabin used to do with Maple Syrup. They mixed in various amounts (it was a decreasin percentage over the years) of maple syrup, and the rest was essentially corn syrup and sugar water. Even the syrup they used was “buddy” bitter syrup. They changed the laws so they couldn’t market it as maple syrup any longer. Now, they don’t even contain any maple syrup, it is all artificially flavoured. Part of that is due to banning of paraformaldehyde so you can’t keep the holes open as long so you can’t run later into the spring.
We used to heat ours, not even very hot, it was on double boilers even. just hot enough to make it run through a filter to get the wax out, you don’t want to melt the wax. I doubt it killed any fungus or bacteria. You can let the wax settle to the top, but we processed and bottled about 1-2k lbs in one day.