Growing green onions or scallions in a glass of water

A few days ago, I stumbled upon this post:
http://www.thekitchn.com/re-growing-green-onions-grow-your-scallions-back-on-your-windowsill-165274

I can personally say that it works! I buy a bunch of scallions and if I don't use them up, I snip off the green parts and stick the white parts, roots down into a shallow glass of water. I change the water once every day and let the roots rinse a little under running water. The green parts will keep growing and you can just continue snipping. Alternatively, you can stick the roots into soil and you'll get the same result.

If you like celery, you can also do the same with those. Cool right?