Most garage guys get it done and out. They don't let it air out.
Do NOT use clorox, besides yellow it will eat the bone away.
Hydro peroxide if anything.
I'm with the otehrs, assuming it wasn't done sloppily, it really needs to air out a month IMHO after its out of water. Even if boiled. Simmered is better than boiled, but I've seen boiled skulls never loose their smell because the fat melted and got into open bone pores while in the water pot....t hats why museums usually only accept non boiled, IE rot off or beetle jobs.
One other thing, You could put the skull in a box with wadded up newspaper, be careful ink does not transfer.... but newspapper helps soak odors. wonder about putting it in a garbage bag with baking soda too possibly for a week?
