I really like Terri's suggestion. You could tell them that you have had so many requests that you considered being a professional consultant on researching methods and materials to use to create jewelry similar to yours. It has taken you years to obtain the info and learn by trial and error to create the items you now list in your shop. Because of the requests and interest in your jewelry, you are willing to save others the time and work by providing them the info. It will take you about 2 hours to gather the data, type it up, and send it. The fee would be $100, which comes for the 2 hours X $50 per hour (an extremely discounted price for professional consultants). If the person is still interested, just let you know and you will happily set up a special listing for them. Then, as soon as the payment clears, you will forward the info on to them. Be sure to thank them, and let them know that you look forward to hearing back from and working with them.
Usually I am not so sarcastic, but there are days. Honest flattery can be great, but so many people have no understanding at all of what goes into making the items listed on Etsy, whether it's time, money or stress wise.