Dry it out, mash it up, and sell it to new age teenage wannabe-hippies
I mix it in a big black bag full of general household waste and dog shit from the garden, dog shit on top. People won't dig in that bag for long once they get the first faceful of turd-whiff. My local disposal facilities have a strict policy on touching anything once its been thrown in, in fact if you accidentally throw your car keys in with a bag of rubbish they won't recover them. They also go over the trash regularly with a big spiky crusher/roller contraption of fear.
If I didn't have that, I'd probably mix it into my normal garden soil, obviously soil ending up on top. If thats not an option, get rid of it a bit at a time with household crap.