Neurotic litterbox behavior

My Gus is 14 years old and has never used the litterbox with any real regularity (to pee). He has always preferred to pee in my laundry, on towels, rugs, whatever fabrics are on the floor. I would think he's being persnickity about its cleanliness, except that he has no issue pooing in it. He is pretty neurotic, and often bored, despite tons of toys and three other cats to play with. He talks constantly, especially when he's bored. Previously, he's been diagnosed as stressed when I leave for a long period, with FUS (Though it was by an overzealous vet, and no one else has diagnosed him thus). He is on urinary tract health food, and still pees almost anywhere but the box. Help, please?

Has he been doing this his whole life? If he has, it may be a bit of a challenge to change 14 years of this behavior. but... here are some things to look at.
1. How many boxes do you have? If you have 3 cats then you need at least 4 boxes. They should be located in different parts of the house, and should be uncovered.
2. What are you cleaning the urine up with? You need a really good enzyme cleaner. Unfortunately there are some that are popular that aren'f effective. Also, if it soaks into pillows and mattresses it's impossible to clean. Cats will continue the same areas unless they are cleaned with a really good enzyme cleaner.
3. Are you using dryer sheets? Some cats are triggered by dryer sheets and will urinate on articles that have been laundried with dryer sheets.

This is just a start...
Marilyn Krieger, CCBC
www.thecatcoach.com