You can bluff your way through vac tests with some air line, a couple of plastic fittings, a vac gauge and some kind of tubing clamp (small locking pliers). By sucking on the open end of the air line, you can pull 10 on the vac gauge, clamp it off and see if it holds.
Same sort of thing can be assembled from parts for pressure using a small pump meant for bicycle tyres or sports balls.
You can test for these things without a Mityvac- but the correct mityvac makes it a whole lot easier to do.
Aww man that’s a good work around for someone like cuinrearview that likes sucking on hoses! Now he will be headed to the shop to find the biggest radiator hose he can...