X10 (or whatever) on the vacuum bleeders being very finicky!

However, after trying amny tricks, the one that works the best BY FAR is to take out the bleeder valve altogether, and wrap the threads in YELLOW plumbers Teflon tape. Get a good several wraps.
Yo ureally should use the yellow stuff b/c it is designed for oil-based fluids. Brake fuid isn't really oil based, but will very quickly disolve the standard white teflon.

Anyhow, pull out the valve, wrap it, and stick it back in. Just be prepared to work fast b/c it wil ldrip like a mofo while you have that thing out!
This seriously decreases the amount of bubbles.

I'm with Roger, I crank the vacuum up to like 25-30 bars so the hose is nearly collapsed, THEN open it up just a hair.
1 vacuum tool tank = time to refill the MC.