I prefer the autosiphon myself, but one way you could create a vacuum in the keg would be to slosh around some boiling water in it to heat it up. Dump out the water and seal the lid. As it cools, a vacuum will develop as the air inside cools and contracts. You'll want to have your racking cane already in the beer, and once you hook up the liquid out post to the keg, it should start a siphon. You would need to vent the keg after the siphon slows down since it will eventually stop pulling, but I think this would work.