Why don't you see if he'll buy the tapes and let you borrow it to satisfy your curiosity about the difference in learning it from a book and learning it from tape. If he hummms at the price tell him LCS has a payment plan.
You might hint that 'older' people find it easier to learn from tapes since many of the don't feel that they have to learn anymore since they left school and the fact that it is such a different method of reading from what is taught at school... I'm generalising to give you an idea how to get around trying to teach him yourself. 
That is not to say that people from any age groups need to experience difficultly learning to PR by whatever method they choose.
If anyone shows interest in what you do it is usually easier to send them to where you learnt it... and say yes that where I learnt to do what I do.
Alex
