Thanks for your answers. I was not aware that I would need to pay anything or atleast had not considered it. The mand I was asking about is a total stranger to me and I don't think I'll ever meet him again. I told him about the suggestions you made for the cause of his prickling tongur, he shoved them aside saying he knows it's none of those.
I'm sorry to have bothered you with that question. I think the service that you do is really nice.