You may be aware of this but if not here it is FYI.
Get the oil before it goes into the renderer's grease bin.
If you take it out of their container you are commiting theft and a lot of renderers are filing charges if they catch you.
It may seem like a waste product to you but to them it is a resouce that they sell to the feed industry or other businesses that use it. It is how they make their money.
I have been into alternative energy/fuels for a long time and have spoken to several people in the waste veggie oil industry. They are not fond of "grease rustlers".
I am a volunteer consultant to Central Alabama Clean Cities, an environmental organization.
I will probably convert my MV to run on alternative fuel when I get one.
A word to the wise for what it is worth.