It only works for as long as you do not sync the device and only after you clear the recommendations on the web site, not the KOBO app (where for some reason you cannot clear them).
I did not know this. Thanks for the tip. I don't sync very often at all, and hadn't really noticed. For that matter, I hardly notice what's at the bottom regardless of what it's showing as I'm too busy opening the book I'm reading. Maybe it has something to do with the general inscrutability of the cover images in greyscale, in conjunction with my bad eyesight.