@Simon @Alan - Swim Cycle Help

I've been trying to figure out some sort of swim cycle for my bacteria but I can't seem to get it right. I can get it to flap back and forth but I'm not quite sure how to give it a flowing movement. I tried following this tutorial but I think because of how I rigged it, I can't seem to offset it and make it look more organic. If there is anything I can try please let me know but there are also other things I can do until tomorrow's lesson if that is easier/better.