This is such a cool way to dye yarn. Maiya mayhem dyes her yarn with koolaide and then she has really neat multi colored yarn to knit with. She has the tutorial and if you go to the bottom of the page she has a link where she and her sons did more colors and then she made them some hats with the yarn they colored.
I love that each skein of yarn would be unique because no 2 would ever come out the same. Something fun everytime.
She does stress that only wool, silk or some other animal fiber will work for this method.
Kool Aid Popsicle Dyeing Yarn
Cascade 128 Chunky Wool Yarn – 8010-Natural