I did my first overnight cook on the 22.5 WSM this weekend. I was very surprised by the way the WSM performed, and I even got a nap in during the cook without using a ATC.
For fuel I used KBB, no water and a foiled clay saucer.
2 ea .99 lb Food Lion butts.
Only had to do a few adjustments on temp and she cooked all night.
12 hrs later running at 250* we are probe tender.
I still need practice on my boxes but the MRS said it did taste good.