Have you ever heard of umbilical cord training???
Frustrated, I searched the internet for help. Apparently small dogs are particularly difficult to house train because they can so easily sneak off and create bad habits. We started out limiting his access to the house and even put a baby gate at the top of the stairs. Well, he's tiny enough he just walks through the balusters and heads on down.
From my research I found this type of training they call "umbilical training." Meaning basically, the dog is hitched to my hip by his leash. No sneaky sneaky to go potty creating bad habits. If he needs to go it's obvious and I take him outside.
While this is slightly obnoxious, and he rebelled something fierce (tiny but mighty) at first, he's taken to it and doesn't seem to mind going with me about my daily chores.
We will break his tiny will. Resistance is futile....