Is your mity vac the metal or the plastic one? Reason I'm asking is I can't remember if the plastic one has the external point the same as the metal.
On the metal one, by the gauge you've got a nipple for outlet, or pressure. When you have the mityvac closed(the lever pushed one way or the other) where you can feel vacuum building when you have it capped, you will also feel pressure coming out of the outlet port.
I have done this numerous times, so I can offer it as good advice. You can use your mity vac as a pressure bleeder. It works on clutch systems because they do not have the residual valve found in some brake master cylinders.
Fill up the plastic catch bottle with clean brakefluid, hose it to the bleed nipple(after you've put a light coating of teflon thread sealant around the threads), with the master cylinder dry and the bleed valve open you can pump the fluid through the slave up the line into the clutch master. When you see fluid starting to build in the master the system is bled, just tighten the bleed valve(making sure the clutch slave rod is in normal position,i.e. not depressed back into the cylinder) top up the master and you should be good to go.
i.e. hook the filled plastic bottle up one hose to the bleed nipple, the other to the outlet port of the mityvac. open the bleed valve and pump it into the slave up to the master.