I discovered a small exploit recently involving Fish, the Squeezer, Empty Food Cans, and the Canning Machine that allows you to get a more or less unlimited amount of Fish Oil from a single fish. Here’s how it works:
Go fishing.
Once you have a vanilla Minecraft Raw Fish, put it in a Squeezer to get Fish Oil and Fishmeal.
Cook the Fishmeal in a Furnace / Oven / etc. to get Cooked Fishmeal.
Combine an Empty Food Can and your Cooked Fishmeal in a Canning Machine to get Canned Fish.
Place the Canned Fish in a crafting grid. This gives you a vanilla Minecraft Raw Fish back (not Cooked Fishmeal like you originally had), as well as the empty can.
Return to step 2 to repeat the process.
I’m not sure what exactly unlimited fish oil allows you to accomplish, but still, an exploit is an exploit so I figured I’d report it nonetheless.