I had to laugh at this!a week after I'm dead, someone will come along and find that the stuff cures whatever killed me, lol.
The problem with any of them when growing along streams is that they drop berries into the water, and colonize downstream. We have places where there was a home years ago with honeysuckle. Over the years the berries would run down hill in spring melts, so there’s a mass of honeysuckle a half mile away. Then birds eat the berries and spread the seeds…There’s also something about the knotweed pollen that inhibits trout populations.
I’ve heard about the goats but they don’t do anything to the root system, which can be several feet down. I’ve also heard of pouring concrete slabs on top of them… it may take a while but eventually tendrils will start creeping out from under it.
Sounds like something from a Stephen King movie…