I've replaced just the clutch MC on a 123 car, and just the slave cylinder on a 201 car.

On the 123 car, I started the car in 1st gear with the clutch pedal out, and drove around for a few minutes in first gear, working the clutch pedal occasionally to test it, and it "self bled" just fine.

On the 201 car, I used the hose-from-brake-bleeder method, had to fuss a bit getting the hose really tight on each bleeder valve, and it worked just fine. Much cheaper than an oil can.

Now I own a a pressure bleeder, but sadly none of my MB's have three pedals...