It would work fine some things to note about old comb, if it ever had brood in it: I melt it in a Wok that I got at Goodwill. The wax has chunks of cocoons in it that quickly clogs filters and strainers. I boil my brood comb in water (as mentioned) I scrape the top off with a piece of window screen then I set up a bucket. Over the bucket I place a piece of aluminum window screen, above that a piece of #8 hardware cloth. I boil water in a pan, and when the wax solution has been boiling for a while I pour the boiling water through the screens / window screen. This preheats the screens and gives me some hot water on the base of the bucket. Now I pour my mixture of slop over the screen, sometimes I even need to adjust the flow as the different screens clog. Let the foul smelling mixture sit overnight. Dump it into the yard. You will have a nice block of wax with scum on the bottom, scrape it off and you have reasonable wax.
Hope I was not off track with this.