This is a follow-up to my first question on the gardening stack exchange. Unfortunately the horrid bamboo continues to plague me this summer. To the point that I'm actually considering packing up and quitting this home: I really wanted a yard with minimal maintenance needs, and now with the bamboo's invasive spread, I seem to have ended up with the very opposite, taking away precious time from the more important things I ought to be spending it on.
A suggestion from the linked post was to apply glyphosate to the ends of exposed roots. Before trying that, I wanted to try a "less toxic" approach because of proximity to kids and carcinogenic concerns. A friend suggested offline to soak the exposed ends of roots in saltwater; the theory being that the saltwater would soak through the root system and kill the plant. I thought to go one step further and try soaking the exposed root ends in bleach, thinking to myself "there's nothing more caustic than bleach - surely soaking a plant's roots in it will kill it." Picture below:
So I filled a couple of spray bottles with 100% bleach, and dipped exposed ends of bamboo roots in it. I taped up the tops to ensure no spillage onto innocent soil. It's been one week, now, that the roots have been soaking this way, and there is no change in appearance to the bamboo roots! I expected some manner of shriveling or necrotization - but there's no change I can perceive at all! So I can't tell if this treatment is having any effect at all.
The reason I'm attempting this is that the root system has grown under the very thick hardscaping that covers most of the area of concern. So it is practically impossible for me to dig up the roots that have grown under in this manner. So I was hoping to find some way to "kill the root system upstream".
So, my questions for knowledgeable gardeners, horticulturalist, and maybe biochemists are: is soaking the exposed end of a bamboo root in a noxious liquid a viable method of killing a bamboo's root system? If so, was bleach a good choice? If so, how long should I continue the existing soaking treatment, and will I eventually see a visible change in the root system so I can know that it's dying? If bleach isn't the right thing to try, is there something else I ought to soak the roots in that will have the intended effect of travelling upstream and killing the root system?