Cats urinate outside of their litter boxes for three primary reasons: urinary tract infections, territorial issues, and a dirty litter box. Cat urine stains can easily be removed, however, the smell that lingers is much more difficult to remove, and if set in, can be impossible to remove. If a cat urinates on a dry-clean-only comforter, it's important to clean the urine and treat the comforter as soon as possible. Most dry-clean-only comforters can withstand the gentle cycle of the washing machine, so it will be up to you to decide whether to attempt to launder at home or take the comforter to the dry cleaner.
Press a rag or paper towels into the urine stain to remove as much urine from the comforter as possible.
Spray a stain treater directly on the stain. Pet stores sell enzyme-based stain treaters, and these are highly recommended, however, a laundry stain treatment will work. To make your own stain treatment, in a small bowl, combine 1 tablespoon of laundry detergent with 1 cup of warm water, and rub directly onto the stain using a soft cloth.
Decide whether to launder the comforter at home or take to the dry cleaners. Go to Step 4 for dry cleaning directions. To launder at home, set the washing machine to the coolest, gentlest cycle, and add the appropriate amount of laundry detergent. Add the comforter. Remove the comforter when the cycle is over. Repeat the steps if needed. Lay the comforter flat to air-dry.
Keep the stain wet until the comforter is able to be dry-cleaned. Spray the area with a stain treatment or a mixture of half water/half stain treatment to keep the stain from drying and setting in. The comforter should be taken to the dry cleaner as soon as possible.