if you shoehorn it into CUPS you might as well just expose CUPS on your home network and use AirPrint via IPD at that point ;)

As kotaKat said, it's possible to use CUPS to talk to non-AirPrint printers with AirPrint.

This is what I do with two 4" USB-only thermal printers. They are connected to a Raspberry Pi running CUPS, so I can print labels to them from within my home network. I never need to print labels from my phone, but do sometimes need to print photos to one of the printers. Avahi on the Pi enables AirPrint, and iOS sees that and lets me do so.