I really like holly great for many things + it will take a thread.
I`ve tried drying it different ways, the best is to quarter saw it but that is quite wasteful & requires large sections. I have some in bin liners at the moment, it has been drying for about 18 months & so far no signs of splits.
Whatever you try you really need to dry it slowly, I`ve some I`m trying to spalt but as yet it isn`t making good progress.
Cheers.
Doug.