Oh look we're about to change something on Crobat again!
Due to this thread
(read the OP, Eo makes some good points) bringing this to my attention, I would like for other QC member to give heavy consideration to making Black Sludge the standard "Leftovers" for Poison-types (with a brief mention of the pros and cons of using it instead of Leftovers in AC/OO). Most of the time it doesn't really matter, since you rarely switch defensive Poison-types into Trick users in UU, but it does seem better to use Black Sludge for those times where you do.
Obviously this would be considered on a case-by-case basis, so here's a list of the viable Poison-types in UU (some of them might not even mention Leftovers in the analysis):
If we reach some consensus, I'll go through and edit them on the SCMS.