Vexing problem /forums/images/graemlins/smile.gif I have some experience with PI. First, Roundup, mixed pretty strong, will kill PI. And I'd do that rather than just cut it at the root because if you really douse the foliage well, you will kill the entire plant, root and all. If you cut it at the root it will probably leaf out again, and fast. It takes a lot of root system to support that much foliage.
Of course, everyone is right, even after long dead you will have to be careful with it, but it has been MY experience that green PI is many, many, many more times as potent an irritant as dead PI.
I am highly allergic to the stuff and still have some on my 40 acres. I'm killing clumps of it every season. The reason I'm highly allergic is simple. 20 years ago I mowed (with a push mower) a 20'x20' patch of the stuff, in short pants. /forums/images/graemlins/frown.gif Needless to say, I had no idea what it was. Needless to say, I can spot 1 leaf of PI in a thicket from 20 feet now. /forums/images/graemlins/smile.gif