you could i guess it's those things you hook to a hose pipe and spray on the house then rinse off so you could just open the container and pour into a bucket with water and use it on the areas you wanted with a sponge or brush. look for it at Lowes or Walmart
I bleached my blue canvas. It worked really well and there was no scrubbing or anything required. I just filled a big tub with ~1 cup bleach per gallon and a half water and threw in a few cups of laundry detergent for good measure. Agitated with a stick for a few minutes, afterwards my canvas looked like new. Afterwards, I treated it with 48 oz. of 303 High Tech Fabric Guard (that was expensive) and I'm glad I did. I had the boat out in a 7 foot swell with 3-5f foot wind waves and took a lot of water over the top. The canvas didn't leak a drop.
TEST A SMALL SECTION TO BE SURE THE BLEACH WONT "BLEACH" YOUR FABRIC. Some fabrics, such as Sunbrella, are bleach safe.