The book is indeed talking about the Electric Cookshacks (that book is so old, it predates the FEC's).
First question, what are you trying to smoke?
You can use it, but what you have to do is use a different heat source (say a heat plate) and maybe a few pellets or even sawdust.
That would be cold smoking.
So what are you trying to smoke that way I can tell if it's cold smoking or warm smoking (based on temp).
A slow cooker is a crock pot FYI LOL...