OK! That makes a lot of sense! We have access to some sawdust. Also there is a lot of fallen leaves around, so I think those could be good carbon sources. It reminds me of compost toilets using sawdust, shavings or leaf litter as carbon layers. Now I am liking this idea even more!

Thanks for all the info and insights :) You've inspired me to try it out. First step..get some EM!