I knitted it into a sweater. Bleaching the swatch gave me some hopes that the color could be improved. I wore it a few times, hoping it would lighten in the wash. Finally, I put it away. Yesterday, I decided that if I'm not going to wear it, I may as well experiment with it. To prep it for the dyeing, I soaked it in a strong bleach solution. You can see the sweater immersed in a white plastic 5-gallon bucket here, with the swatch floating on top.
My dye bath prep was rudimentary. I simply put 3 gallons of the hottest water I had (about 125 degrees, straight out of my hot water tap) into the bucket, added a cup of salt, per the directions, and a bottle of Rit dye. (By the way, K just repaired the hot water heater and set it to the highest recommended setting to make sure it was working. That's why I know how hot it is. Since we will turn it down soon, the time was right for dyeing this weekend.)
Here's the swatch after rinsing and drying:
It came out a bit darker than the sweater I dyed later. Most likely, the swatch took the dye better because it was more bleached to begin with, and it went in first when the water was hottest and before any dye was exhausted by the other articles.
Although it looks plain brown from a normal viewpoint, if I look closely, I can see variation in the fabric. I assume the lighter patches have more acrylic content. (Clicking on the photos gives you a larger view.)
I'm satisfied now that Cotton-Ease can be dyed. However, I'm less satisfied with the results I got on my sweater. Dyeing a garment presented me with another problem--I didn't get an even tone all over the sweater. It's still drying, so I will post the results later when I can get a modeled shot.