I am having the same problem with Sadie going on the edge of the wee-wee pad. I don't understand the bottle trick? Do I line the edges with the water bottles? I don't think toys will work as she has ADD and plays with all of her toys all the time sometimes two at time. 
 
   
Also, how do I get her to poo on the pad? She will go near it but not ON it? Typically so goes in her favorite spot in the hall. Every once in a while she will go on the pad, and I praise her for it. But that is a miracle.