Some might call it overreacting, but rather being safe than sorry is very smart and responsible. And I agree about nuke's idea being awesome!
Incineration is an option but if you cannot control incinerating instead of vaporizing then it could be a safety hazard.
I'm not sure if adding a strong acid or base would convert it but then you'd have to dispose of that and neutralizing probably makes the whole thing pointless so doesn't seem practical.
But it does raise the question: would you also be this careful disposing the corresponding 2C-X? What if the amount of the 2C-X was much bigger and it amounted to the same number of doses?
From what I understand things like cocaine metabolites are detected in waste and they try to do calculations on that. Also apparently a lot of medications are found. But if we consider how many coke users are pissing away unmetabolized cocaine and how many (or few) people would be flushing an NBOMe compound, which would be realistically expected to pose a problem? It's just a question, I think that on principle none of it is any good.
I am reminded of recycling. In some cases recycled goods are just rejoined with the rest of waste and the only apparent point is psychological conditioning which would hopefully lead to more conscientious behavior, and maybe preparing people for the real thing even though the disposal process is still in development. (My dad did environmental management for a while, and it is very crookedly interesting it is, some of it is treated phobically and with obvious lack of understanding while other stuff is treated carelessly).
Ideology can also get complicated and philosophically or analytically debatable, the many are made up of many of the few. Short-term futility can seem like a very poor principle to live by and an opportunistic justification, but can at the same time be proven realistic using stastistical data. So what to do?
I propose you use nuke's suggestion because it is still fucking awesome anyway!