ok. so finally I've found a way to produce quite promising vacuum pump: the compressor from a refrigerator.
It looked very promising and passed the first test (sucking air out of a glass until its cover collapsed and got sucked in - perfect.)
I attached it to a vodka-bottle and hoped that the water in it would at least begin to boil (this would be step 2), BUT nothing happened.
There must have been negative pressure, since there was this nice "pffffft" after removing the hose from the bottle... hm...
I'm lacking a manometer, so I am completely unable to tell how successful (or unsuccessful) this test was. *sigh*