I actually use human incontenency pads (e.g., Depends)! If you go to CVS or Walgreens and go to the Depends isle, you will see that they make regular square pads that look exactly like the dog pads! They have a small size that works for dogs, or you can by the X-Large size and cut them in half and place them in a pad holder (this way, you get 100 pads for $7!).
