I can only offer advice, at this point when looking for wvo. I started by finding the closest restaurants/places to eat to my home and asked them.
A deli (<1 mile away) has agreed to give me ~5 gallons every 2-3 weeks (until summer, where it will be more frequent). A chinese restaurant near me (who was paying to get rid of their oil) has agreed to give me theirs (~5 gals a week). A local diner asked me to come back in a few weeks, but looks promising.
My advice is to visit these types of places during non-busy hours. I have found success between 10-11am, the managers/owners will have more time to talk.
I like to emphasize that I'm local and will work on their schedule for pick-ups (weekly, bi-weekly, monthly). Also emphasize 'free of charge'. For the chinese restaurant, it helped I had a 55 gal. drum to drop off (w/lid). They are very happy to get rid of their (small dumpster sized) oil bin.
They were also happy to get rid of a few 5 gallon buckets (w/lids) and a carboy (5 gal SVO container).
I hope that helps.