I've done the 2X4 thing, it works okay for the right rear tire, but takes forever to do the RR or up front. Don't really like doing it with the clutch. The vacuum thing works great. Just don't reuse the fluid/dump it back in the master cylinder. That stuff does go bad after a while. detergent breaks down and, like motor oil, the viscosity starts to weaken. Best to get ya a couple pints, use one on the brake lines every couple of years, and another as a spare when things start leaking and another to open on your clutch system.

91 Jeep Wrangler YJ, carpet, tires, trailer hitch. yea....