The problem with tye dye is that the colors radiate out from a central point.  I have to dunk the entire part into the color and it would fade the direction I dunk it and since I cant dunk the center of the part first, it's pretty much impossible.  I can get pretty creative by painting the colors on if the parts aren't round.  I could also start in the center with a color, mask it, bleach, dye, mask, bleach etc to get a pattern close to tie dye.  Would take a lot of work but I'm 100% sure I could do that.  would cost a bit more in masking though.