I was worried about my dog ripping up the piddle pads as well if we weren't present. I had heard stories about the dogs eating the piddle pad and then the contents expand only to find the dog dead upon return....I decided to order the piddle pads from a website:
www.piddlepads.com....they came in the mail very promptly. I have to say, they are wonderful. Not only do they hide the piddle spots, they are waterproof, chew-proof?(can't be shredded) and easy to clean in the washing machine. It may just be what you need!