I do a low immersion thing that might be interesting to you.
I use regular powder dye (like Rit). What I do is called low immersion. Basically, you just put the thing you want to dye in container that just fits it ~ tightly. You can add the dye on top and bottom or get creative. Add water (not much should fit). Then, pop it in the microwave for a little while because heat activated the dye.
You could also tie it and you can experiment with how you 'fold' it into the container. Let it sit for at least an hour ~ or overnight and then dump it into the washing machine. If you add the dye water it will mellow out the effect, it's up to you. It's fun.
This is an adaptation of a process used for reactive dyes. I say this because if you look up the instructions, know that you should probably use 'complimentary colors' if you're using Rit.
You could also just tie it up with rubber bands and through it in the washing machine.
Troll? Here's me...