I use fleece bedding that I ordered from a lovely place called "The Hoghouse" on Etsy. I do have a cold water only machine; perhaps it would be better to take their bedding to a coin laundry? The detergent I use is from Aeon and it's the "Free From" line. It's supposed to be free of parabens and other artificial stuff.
Since I got my boys, I moved all of my perfume and scented candles out of the room. I never spray them in the same room. An air purifier is a great idea. I've got one I think, but I believe it's mainly a dehumidifier? It's pretty big and can be used to dry clothes. How much was your purifier?