It's not really an accessory and it certainly isn't a DVD, but it is something any serious puppeteer might find helpful.  It's a book-like sort of thing filled with all kinds of information (written in a pretty funny way) that would/could/should be valuable to a puppeteer. Techniques, voice characterization, script writing, stage construction -- all this and more is on this e-book on CD Rom.  Also available soon as a download.