Ah, many years ago I swiped a compressor off an old waterfountain that the condensor had developed a leak and it was junked, used it for years to suck down systems, then I bought a regular vac pump from a buddy that was getting rid of stuff.... much faster now..... Plus I love how it "burbles" (noise that it makes.)
That would be nice, from all accounts the venturi pump takes quite a while to achieve the correct level of vacuum, and requires a LOT of compressed air to do so (so no cheapy little models, gotta use a big boy)
On the other hand, it cost me $15.... haha