This is so stupid...it feels like it shouldn't work, and yet IT DOES!
Mag with Max range + some survivability (Primed vigor, but I guess any hp mod will do) + Preparation (start on the right foot) + energy siphon
As previously stated, make sure u are facing a ledge they can fall off of when you pull them towards nothing.
Finished when I had 2 more canisters to spare.
Thank you kind sir for suggesting it in the first place.