I managed to get the snow dyeing rinsed and hung out to dry yesterday while the VHC was asleep, though as you can see I didn't get it ironed, and those threads are going to need a quiet evening when I'm feeling patient. The real colours are rather darker than this looks, and not so green. I used Kemtex Cerulean Blue and Jaquard Teal with a dash of Jaquard black in each.
I read somewhere that snow dyeing causes dyes which are a mix of colors to split into their constituent colours, and it definitely happened with the Teal, leading to blues, greens and purples. Nice, but not what I wanted.
However, the method of just bunging the slaked dye onto the snow worked fine, with a good spread of colour across the cloth and few if any white bits, possibly because I didn't bother with complicated arrangements for draining off the liquid. There was relativly little liquid anyway, as of course snow contracts when it thaws.
Today I took advantage of our remaining snow and had another go, using Cerulean (which is a pure dye so shuold't split) with a smidgen of black. It will have to sit there till Friday or possibly Saturday before I can rinse it out, as it's another child minding day tomorrow, and the postponed Contemporary Textile Workshop on Friday.