Here's a video I made on it to help you figure out. The idea is to get two cannibalizes in between a tick, and then wait a tick so you can easily see the numbers stabilize. It is more consistent than trying to canni dance every tick, which isn't recommended. The video description has the macro I use. Also, there is a comment on the video in which I give a more detailed description of what to look for.
https://www.youtube.com/watch?v=7K7oSx2vplg