Try one of those orange citrus cleaners / de-greasers.

The eco-friendly orange cleaners are great; good old lemon juice will go a long way toward cutting grease, too. If you need to scrub, try baking soda.....

dawn dish soap really does cut grease.

Set the bottle in the sun, upside down on a thick layer of newspaper. The sun's heat will thin the oil and gravity will drain most of it out - keep freshening the newspaper! Then try pre-soaking using very, very hot water to fill the bottle to the top. While the water is still very warm (about 20 minutes), most of the remaining oil will have risen to the top and can then be poured off. A simple hot-water and detergent (yes, 'dawn' is good) wash should remove whatever oil remains. Don't forget to rinse several times. I've done this with several plastic containers - the most difficult part is have the water as hot as possible without melting the plastic!