i've been trying to figure out how to use my castings without making a tea or whatnot but i haven't been able. how do you water? i soak or spray and it seems to flush all the castings out... i don't think there's anything in the castings that would deter the millipedes. in fact, i thought they often ate stuff that's decaying. perhaps the castings are already too decayed for them to eat so they leave.