I admit I always thought it was illegal to plant it, so this has made me do a bit of 'googling', interesting reading. not illegal to plant but you can be prosecuted if you allow it to spread onto other land.
I'm trying to remember how much my goats liked it (in a previous 'life' 1980's), I think I used to walk them up to a patch, but they didn't make much headway with it, now the whole area is covered with it.
Hope the bath can control it, beware the roots can go down a long way (though the plug hole?) then may escape?
I'd try my goats with it but I'd be worried about it starting up here.