I wonder if the drug would work on felines, combined with the technology/approach here https://www.youtube.com/watch?v=AnpJBI_502U you may have an ethical way of dealing with what's a huge problem in Australia. I've been keeping an eye on this technology for a while now.
https://senestech.com and https://en.m.wikipedia.org/wiki/ContraPest
No gene editing required.