"Do you really think the chinese reaction to a threatened embargo would be to fold quickly?" if they have half a brain they would! they can't survive without exporting!
And NK can't survive without China!
And over half of the Chicom exports go to the countries I listed! OVER HALF!
I think their reaction to such an action (even assuming we could get japan and ROK onboard, which i strongly doubt at present) would be to escalate, not back down.