This is certainly interesting and, from the (admittedly) little I heard, the person who posted the recording on YouTube makes valid points (other than the one saying that the Alpha Course does not present the trinitarian position - it does; the Elim church conducting the course however seems not to have) but I believe he takes the wrong approach. He argues doctrine. It is far, far more effective to use the Bible Teach book to chip away at the confidence the JW has in the Watchtower organisation. This is done superbly well by Wilbur Lingle in his treatment of the book, which presents for the Christian a step-by-step guide to be used in the book study situation. Faithful Witness, I didn't see this post until after I messaged you - I answer it so that others have the opportunity of taking Wilbur Lingle's approach. I am using it with a JW neighbour I am discussing things with to great effect. If I were you I would gladly do the book study with your elderette - but only with Lingle's guide well-prepared a chapter at a time.
If anyone is interested I can send either the file or Wilbur Lingle's contact details.