Removing labels from beer bottles

I've been experimenting with making my own beer since October time, with some acceptable beers being produced. I've tried making Woodefords Wherry, which took ages to clear, but is now drinkable, and some Coopers Bitter, which fermented very quickly, and was drunk almost as quickly.

Anyway, I have a batch on the go at the moment which I want to bottle, and I had a load of used bottles from which to remove labels and clean. I soaked all the bottles (and they are from a number of different breweries), and on some the labels just fell off, and the remaining glue was easily removed using hot water and a small scrubbing brush. However, the bottles from Adnams proved to be a total nightmare. They are plastic, and peel off OK but left a really sticky residue. I tried, in this order...

1. IPA (not the beer - Isopropyl Alcohol)
2. Brake and clutch cleaner.
3. Meths
4. MEK (Metyl ethyl ketone - this usually shifts anything)
5. Petrol.

The petrol finally did the trick! Using a cloth and plenty of petrol, the glue dissolved quite quickly, and a quick wash in detergent finished them off. Use gloves for this - not latex as this dissolves in petrol - use nitrile gloves.