Cast Iron Drain Plugged (Snake or Jet)?

[Molo]

Through a process of elimination we have determined that a 20' section of 3" CI Pipe that is 100% plugged. This particular section of pipe is 50 years old and in the concrete floor of the basement (house is the same age). The pipe merges with a 4" pipe that leaves the house, but this is not plugged. There is a cleanout access to the plugged 3" pipe. The CI pipe that is above the concrete floor is in very good condition, but I cannot tell about the section that runs through the floor.

My question is should this pipe be:
1. hand augured
2. power augured
3. water jetted

Thanks in Advance

 

[Tom Sawyer]

I always start with the power auger.