It isn't very difficult to learn how to use the Dolby Model 361. There aren't very many parameters to work with outside of some basic transport and monitoring buttons. You kind of just let it do it's thing once it's all good to go, as the only buttons it has are for putting the noise reduction in or out, record, play/remote, and then for monitoring either normal or to check. It also has an analog meter. A manual isn't necessary here, nor have I seen one.
The Dolby Model 361 will actually do a pretty good job of getting rid of unwanted noise or hiss, but since there aren't any real parameters to change the gauge of the reduction, it's somewhat limited in it's capabilities. We've got a pair of these in the studio where I work, in addition to a Dolby 360. They don't get used very often, but every once and a while someone will decide to use them. They are definitely suited best for use with a tape machine or for when you've recorded to tape.
While I'd prefer to use a modern day noise reducer since they are more in depth, the Dolby Model 361 is pretty cool for what it can do. I probably wouldn't recommend buying one unless you're a professional recording studio where anything might be needed on any given day, but if you can get one or two really cheap and might have a need, you might as well go for it. So while not exactly using modern technology, he Dolby Model 361 is an adequate noise reduction system that's still worth using in the right situations.