Disrupting the chemistry of oobleck so that it behaves like a newtonian fluid
Disposal isn't a problem - add more water as you dump it down the drain.

There are two extremes to ooblek:


Almost all cornstarch and almost no water: this is a dry solid or slightly wet starch. No big deal.
Almost all water and very little starch: this is some water with a little bit of starch mixed in. Sometimes it clumps or falls out of suspension, but it's also no big deal.


The non-Newtonian mixture occurs at intermediate ranges.

Since cornstarch will degrade in the sewer system (e.g., feed bacteria), it's safe down the drain. Alternatively, I compost it.

But if you're worried about non-Newtonian behavior, you just add more water.