Mmm, I'm thinking sealing failure effects are somewhat correlated with the actual seals that are failing, right? Or, at least, some vague direction of their esoteric effects is influenced by the nature of the failing seal, as well as any seals that are nearby (I distinctly recall Kagome fretting about that). Right?
What I'm thinking is, we grab a ton of Wakahisa and Chakdar seals, wrap them around a 20-SIN tangle, hook the thing up to a timed explosive, then drop it on Oro's compound and make ourselves scarce. The 20-SIN produces a failure, which then chains up with the Wakahisa and Chakdar seals, ideally nudging the failure's effect towards the chakra-related and proximity-based. The whole thing then, if we're lucky, starts to... adversarially affect any nearby chakra signatures, which happen to be primarily Orochimaru himself. Chakra effects seem pretty esoteric and fundamental, and if Oro gets tagged with something like the Blotch, except even
worse, he might not have a ready answer for that, and it might even circumvent his immortality.
Better yet: do we have access to any Orochimaru-infused seals? Does he sell them to the Tower, say? If we do, we buy out as many of them as we can, then add them all to the SIN, so that there's a particular chakra signature saturating the environment the failure is happening in.
And if you think this idea is insane, need I remind you that
Jashin is provably on our side, and His is the will behind the failures? He shall aid us, if we but allow Him to.
I think this is all a pretty sensible contingency plan, all things considered!