The spray is called Feliway - you can get a diffuser that plugs into a power point, and also an actual spray to use on soft furnishings etc (but not on the actual cats!). We've had a few pee incidents here too. One thing to get checked is that your cat doesn't have a UTI - the first pee incident we had, our female cat peed on the couch and when I took her to the vet she had a UTI and the vet said peeing on the couch was her way of telling me something was wrong.

Also with the urine stains you need to use an enzyme to completely remove the stain, otherwise the cat may reoffend - or the non-peeing cat might do it too. Apparently Biozet washing powder is good, but for stuff you can't put in a washing machine eg the mattress, there's a spray called Urine Off specifically for cat urine (they also do a dog version) you can get it from pet supply stores, it's a black spray bottle. They recommend you use this spray first before you wash the items with anything else. It seems to have worked for us with our couch covers.

Regarding the feliway, it is expensive if you need it on an ongoing basis. I bought it from an Aus eBay seller so that I had an Aus plug-in to use (it was around $70 I think for the plug-in and one refill, a refill lasts for a month), now I am buying the refills from a US eBay seller and it worked out to be AUD$90 for six including postage. If you want the seller's names just PM me.