have you ever bought used items for your cats? I found a pet carrier and litter tray on gumtree for £15, I need a bigger litter tra as neither can seem to put their business in the tray anymore... must be getting too big. plus this one has the detachable lip, so I can finally put liners in it without them getting dragged in the tray. litter tray is approx 44cm x 30cm carrier is 50cm x 35cm and 35cm high I know I should probably wash them up before putting my cats in them, but what do I wash it in? that won't irritate the boys?