I wouldn't do that because that would feel weird,

I mean, it's basically homemade spam. It's kinda weird.

To me that's more ethical than killing of billions of animals, and the latter is considered ethical.

I think most people would actually consider factory farming unethical, they just put the blame on the producers for treating animals like shit. And the producers are locked into a race to the bottom for competitive prices, so they'd blame the customers/market conditions.