First off...this made me laugh. So thank you for that
Now, in my opinion you have done your part. You sent a message with the correct information / care to the person. If they still believe their way is best, that is on their shoulders. I've sent the care sheet emails, gotten some nasty replies, some nice ones, and no reply at all. I don't keep myself up at night wondering if they are caring for their snakes properly now, I just hope that they take advice well, and go on about my business.