I hope this kind of question is allowed, so sorry if it's not. Not sure where else to look

I've got an elk skull that we found while hiking out on my balcony right now, there's no skin or flesh on it but the brains are still in there and rotting like crazy. What's the best way to clean it out? I currently live in an apartment and have a plastic bag over the bucket the skull is in to contain the smell, mostly to avoid complaints. I'd love to know if there's a way to get it clean at home, but if not I do have access to a friend's farm. Just want to get all the gunk scooped out before I throw the skull into some peroxide for a day or two.

Image of the skull is attached. Any help/tips would be greatly appreciated!