To properly answer your question, at least if you’re in the US, most of the auto parts stores have a container you can take your waste oil to. You just ask them if they have a place for you to dump your waste oil and they’ll show you. It’s normally free too, as it’s kind of part of their business model. If a customer can’t get rid of the old oil most people won’t change their own which means the parts store won’t sell any oil change supplies.