I've found the connection! There is an entire site dedicated to the history of Santon. Santon Church, Santon River and so on. If you're interested go to:
http://www.isle-of-man.com/manxnotebook/famhist/v09n1.htm#10-29
I'm glad to see that Santon is a Manx name. There are some French clay dolls also called 'santons' (little saints). No relation.