Natural dyes for handpainting?

i see dharma trading is selling natural dyes now. i was wondering, though, their instructions seem to be for immersion method and i am more interested in handpainting. is it possible to use the natural dyes to make a dye liquor to use for hand painting or are they better suited by immersion? I realize the mortar and such will still be necessary, but aside from that. It says the dye needs to be simmered for an hour, but could I just make a concentrated batch and simmer that for an hour instead of setting up an immersion pot or something?

Thanks!

Sean,
You can hand paint with natural dyes, then place in a simmer pot or wrap in plastic wrap & microwave.

An enamel roasting pan with a bit of water in it and a rack to hold the fiber up out of the water & a lid will work. Keep the water simmering.