Assuming this is for dogs, and assuming your dog is house trained (no accidents for nine months, aside from medical issues), and given that I have helped potty train tons of dogs, I would say you are asking for trouble using this, and you are probably gonna get it.

Your dog is going to get confused and you will have a big problem on your hands not easily corrected.

SG

I had my first experience with the grass4upetpatch. My dog didn't use it right away. I put it outside first for a couple of days, brought it inside with her own scent on it. I waited until she had to go potty, then said "go potty" and rewarded her when she did. We were gone all day and left it out for her. She got the idea and didn't go on the carpet for the first time. It will take time, but she's getting the hang of it.

The grass4upetpatch is fake grass, and IMO, a colossal rip off at a cost of over $200!!! You could make one yourself with fake grass and a rubbermaid container for under $20!

The $25 one is real grass. I wonder how long it will live though -- dog pee burns grass and kills it. I think it is best to have a dog that is fully house trained, but I am not convinced it will be a big problem to use the indoor one in addition to going outside. Keep us updated on how it works out.

I haven't used it - and am not a huge fan of anything that teaches dogs to go inside.

However, that said - both of my dogs at one point decided it was okay to pee on the lawnmower and any of the grass clippings that fell off of it - but never ever peed in the house or anywhere else they weren't supposed to. We made them stop, obviously - but that makes me think that maybe bringing the grass indoors wouldn't be so bad, but it could still lead to issues.

weed30, the grass4upetpatch is actually real grass. The other is not. I got it, spread the grass seed on the mulch with a gallon of warm water. Covered it in the containers sent to me and I grew grass. It's very thick and lush just as they showed in their ad on ebay. It took a few times before my dog got the hang of it, but she loves it now. We only use it at night and days that I am not home, but we still exercise and go for our daily walks or bike ride, so it's not to be used in place of exercise. But, it's great!