Silky Terriers

Working with a 2 year old Silky which was adopted from a shelter just 2 months ago. He is a wonderful, loving little guy who seemingly cannot be convinced that the house is not his potty.
We've tried puppy pads, crate training, the "clicker" method and scheduling, all without much success. I take him outside first thing each morning and try to wait him out, but if the grass is wet, he won't even consider getting off the concrete walk. I have to get my feet wet and lead him. Sometimes, he refuses, even then, until I relent and bring him inside,where he will promptly poop, many times.
It's been suggested that a litter box might work. Anybody tried that? If so, what do you put in the box . . . kitty litter?
It's also been susggested that picking up the "gift" and taking it outside along with the dog to a place where we would like him to go, put the stuff down and say "outside", repeating this action until he gets the idea. Any tried that?
I know it is a characteristic of Silkys to be hard to housebreak, but there has to be a way.
Anybody know what it is?

We have a wonderful, fully potty trained Silky named Bentley. We got him at 6 weeks and he is now around 14 months. We had the same problem and we moved his poop to a puppy pad and placed it in the opposite side of the living area from his food. When he peed, we would grab him quickly and place him on the pad. We started with 3-4 pads in different locations to always have one near by and as he peed a few times, we would then clean the pee, and place the pads over that spot. He would then return to that spot to pee and go on the pad. We would move his poop to the one pad where we wanted him to go most often, and gradually reduced the pads down to one. We live in the upstairs unit and it's not really easy to take him up and down every time, so we just kept using pads. If you want however, if you are successful getting down to one pad, try moving the pad a few inches a day towards the outside door. When you get to the door, leave it there for a few days only, then, move the pad to just outside the door. Then, you will have them trained to let you know they want to go outside to go and you can just get rid of the pads all together. I hope this works.

The process we used ( PADS)does not require waiting them out. As this can take hours, it's not very feasible.