I recently purchased a litter locker. I just love it! I got a refill with the locker and purchased an addition cartridge. I noticed that the cartridge looks simalar to a diaper genie cartridge. A diaper genie cartridge cost about 6.00 at walmart. A litter locker cartrige at the petstore cost about 10.00. I am wondering if anyone has tried to interchange them? It would be much cheaper if I could buy the genie cartridge.