So.... I've been wanting to try this for a couple of years, and finally got there yesterday! I soda soaked a piece of cotton muslin, scrunched it and put it into a small bucket. I set it outside overnight, but our temps didn't get down to freezing, so I put it into our freezer for an hour. When I removed it, the fabric was stiff, aka, frozen. I applied 3 colors of procion mx dye and let it set for 6 hours. Then I rinsed and laundered with synthrapol. Here is the result:
What I love is that the dyes wick much more intricately as they slowly move over the frozen fabric. I have gotten somewhat similar results with regular low water immersion dyeing, but the markings here are more pronounced. Today I am trying the technique on a shirt, so I'll see if it works as well on jersey as it does on muslin.