What happens to used cooking oil?

if you keep it for a while it starts to stinkWhat happens to used cooking oil?
It goes into bio-diesel engines, I hope.What happens to used cooking oil?
Throw it away........... if used your food will taste awful and it will burn.
It gets recycled.
yeah
When do you consider it ';used';. I eat some and wash some away with brandX detergent. That all goes to the same place in the end.
It gets thrown out or used as fuel for modified diesel engines.





I dump mine on weeds...