"hi i'm sorry to bother you, my name is Sean &#$*&#&^ I live *&%*%&*. I was in the area looking for some old woods to do some metal detecting in and I noticed your house. It's a beuatiful home.. I was wondering if maybe I could spend some time in your yard doing some metal detecting?, (at this point depending on the pause I can tell if I should push a little more if they say no), "you would never even know I was here, I make a plug (explain what a plug is) and then i replace it and youll never know i was there. If I happened to find anything personal or of true value I would certainly return it to you", " This is where they will ask you what are you looking for ? Have you found anything worth money? (this is where I say Im really looking for old coins, The oldest I have ever found is a 1722 colonial copper,,,They will usually say WOW I bet that was worth some money, simple answer) " I wish, its worth about 6$".... This is where they realize they dont have treasure in their yards and usually say sure....
(mind you manicured yards are alomost always a NO)