What's really interesting about Franklin electrocuting chickens is that electrocution went on to become the predominant method of killing chickens in the US poultry industry until 2017 when the largest purchaser of chickens, McDonalds, switched to using asphyxiating gas because activists were upset about the electrocution. Non-McDonalds chicken though is still killed the "old fashioned" way - through electrocution pioneered by Franklin. The electrocution doesn't actually kill the birds, it stuns them and makes them rigid prior to a giant saw cutting off their heads.

Here's a video of a typical poultry plant, though this one is in Mexico it's identical to US operations: https://www.youtube.com/watch?v=hMSNGZh60zY

(Warning: do not watch if you can't handle it it's exactly as described.)