I to had mine in a 20 gallon tank, with heater and screen. Bone out skull best you can, remkove eye's an the brain with a pice of wire, let it dry for a day or so in the sun away flys under a screen, A good size bunch of bugs will clean it in a week. I think the key to it is remove as much moisture as you can before hand, cuts down on the stink and they will clean it faster
------------------
Keep your hooks sharp and you powder dry.
Wildoats
"The expactations of life depend upon diligence; the mechanic that would perfect his work must first sharpen his tools."
Confucius