When Homer finds out from Apu that there is a local business buying old grease, Homer sets out to be rich. He buys $30 worth of bacon, feeding it to the dog, in order to harvest the extra grease and sell it. He spends hours frying up bacon only to earn 68 cents. He doesn’t seem bothered by his losses since his wife (Marge) paid for it. There’s one problem Homer hasn’t realized yet; Marge gets her money from Homer.
Thanks to Alex Marsella for the clip suggestion and summary!