With my first Janome New Home DC1050, I bought a generic walking foot off Amazon and it worked just fine.
Crackers-I have heard too, that you should not use a walking foot for reverse stitching, but not the reason why. That said on my Janome 8900 memory craft I recently had to replace my walking foot. A small spring went missing on it and it would no longer work. I used this walking foot for a couple of years AND reversed stitch so I am not sure if it was just lots of use or the reverse stitching.