Chess audio books, a bad idea?

At one time, it was possible to buy cassettes with chess instruction. One was supposed to listen to them while sitting in front of a board and playing over the moves. In the market, I think that those have been replaced with various sorts of video instruction.
"... the majority of DVDs and videos are best suited for introductions to their subjects and are therefore good teaching tools. If you're looking for comprehensive theory, there's no doubt that you'll usually get quite a bit more from a good book on the subject. But DVDs can contain some surprising gems even in that respect, and in any case they are a good way to add some variety to your chess study." - IM John Watson (2012)
http://theweekinchess.com/john-watson-reviews/chessbase-training-dvds-and-downloads
http://theweekinchess.com/john-watson-reviews/chessbase-dvds-and-downloads-part-2
Since audio chess instruction books seem to be gone, it does not seem to matter, but, for what it is worth, I do not think that they were produced with the idea of enabling one to remember a 20 move line.