Waldo,It depends on the values in the particular guano,you need 1 with a higher pk,with worm castings are they fresh or store bought?I'd go and read OSGs thread on worms.
OM,I've never heard of ringworm from poo in this country.I come from farming stock,been picking up cow pats for 40 yrs,helping and crutching sheep for 35,never has this condition arisen.I guess we are the lucky country.
Toker,Those bloody things are way over priced,by all means,if you need small,build your own,secondhand pc cases are dirt cheap fans too grab a light n socket,pump for hydro and Bob's your uncle.
Have fun,experiment and be proud of your creation.