Vacuum cleaners do not generate much vacuum and for vacuum degassing you need 20" Hg negative pressure.
Probably the cheapest if you have an older car with a vacuum connection on the inlet manifold is use this. An engine just idling will generate enough vacuum in the manifold.
I had posted some additional comments in this thread:
http://www.cnczone.com/forums/showthread.php?t=78371 (Vacuum Pump)
You can make a vacuum pump out of a compressor and probably you could rig up something temporary just from the intake port of the compressor which would give you enough vacuum.