[kjc]

The absolute main thing with potty training is to catch them pottying on the pad, or whereever you want, then massive praise (like they've never heard before) and a great treat and petting as soon as they're done. Also as they are finishing the potty, add the command 'Go potty' or whatever term you choose to use. But use the same term each time.

Some dogs do not understand being told 'No', sounds like he may be one of them by the way he runs away and hides under the couch. I would not tell him 'No' at this point. He may be thinking that pottying anywhere is wrong, and just doesn't understand that you mean 'No potty here'. Also because he prefers to potty 'in private' indicates he is unsure of doing right or wrong.

Normally the key times he'll have to 'Go potty' are when he awakes in the AM, after naps, after a meal, after a play time, after home grooming, and before bedtime. Exercise can also stimulate them to have to relieve themselves. Start with offering him the opportunity to 'Go Potty' every hour or two, then increase the amount of time inbetween as he becomes more trustworthy. (You may need to start this on a weekend when you are home, and plan for two days or more of intensive training)

As an alternate to tethering, you could set up a room (the kitchen) with potty pads and confine him at the key times until he 'goes', then massive praise and a treat. You could hide behind a wall and spy on him to catch him pottying on the pad, then do the praise and treat afterward. Also confine him to the room you are in to keep an eye on him. As he learns, he will want you to see him using the pad to get his treat, and many learn to fake a pee to get a treat.

Yorkies will learn faster through 'positive training' which basically means rewarding them when they do a good thing, as opposed to any kind of verbal or physical punishment. Once they 'learn' what makes you happy, they will repeat that action because they want to please us so badly. (or they like treats, lol)