can I cook a BBQ sauce on the WSM?

[benkeenan2005]

basically i'm a lazy cook and just trying to fill the WSM with meat and 10 hours later open it up and eat everything.

I'd like some advice on doing a BBQ sauce low and slow, plan is to put a sauce in a pan and stick it on one of the grates and leave it for 10 hours. So need some advice on a recipe and also how much water to add given that it will be reducing quite a lot.

AIming to get the smokey flavour into the sauce too.

I assume people do this all the time so hopefully someone will have some ideas as i cant seem to find anything anywhere.