It drove me nuts at the time that I couldn't remember the name, but I
just saw the commercial again.

It's called the Grass Samurai.
http://www.grasssamurai.com/custompage.asp?page=1

I'd be interested to know how it works.

Here's what threw me off:
"If your cutting swords ever wear out, we'll send you
replacements...FREE."

But they include 24 of them in the kit. So if they don't wear out,
wouldn't I just need 3?