Well, you could detox it with mushrooms. You'd have to mix it up with horse poo,
compost that, grow portabellos in the result, and then use the spent mushroom compost as a top dressing for some wood-eating mushrooms for a year or so, just to be reasonably sure that it's detoxed well enough. Even then there may still be things that resist fungal decomposition, and of course you probably won't want to be eating any of the mushrooms that come out of it until then.
Overall, it would probably be a lot less work to just take it to the dump.