I think I would wait 'til I finished it to wash.

Can you spot clean it, then give it a good washing once it's finished?
Maybe a spray bottle with a touch of Woolite or some such, towels...spray bottle of just water to rinse...blot blot blot...

I'd get some of the enzyme cleaner from a pet store and spray it with that so you can get rid of the smell then wait until you finish the project to launder it. The enzymes work very well to eliminate the smell.

I've used Nature's Miracle enzyme odor remover in the past with good results:

www.discountpetmedicines.com/buy....htm

Also, vodka in a spray bottle works wonders... though I've never tried it on urine.

I'd definitely get some sort of urine treatment on it right away. My experience has been the longer it stays in material, the harder it is to get the smell out.

when we were in Africa a large cat marked his turf on a nice sweater.
We poly bagged it and took it home. It was a nice hand made Scottish sweater.

The cleaners couldn't touch it. It still smelled like a Lion.
My friend told me to try hydrogen peroxide and any laundry soap in a fifty fifty mix (1cup of each), put it all in a poly bag with a gallon of water and put it aside for a week or two.

I chose two.

The smell was mostly gone after week two.

I put it away with fresh fluids for another week.

Then one more week with a cup of Baking Soda in a gallon of water ( my idea)

POOF no smell.

My 12 yr old kitty just left me after going through kidney failure. During her last weeks of life she peed on everything she wasn't supposed to-including a pile of fabric remnants. I found that hand washing in diluted white vinegar was best for removing the nastiness. It will probably take more than one soaking. Good Luck, Beth

ps-if the litter box is clean and kitty keeps up the random peeing, get him/her checked for a possible urinary tract infection.

apple cider vinegar