I use it - works fine for me. There are a couple of options - I think there's a PDF on the website that you can print and cut out a window on each side of the sleeve. Just slide the right barcode into the window.

I just hold my fingers over the codes I don't want read, and that works fine.

The other thing is that sometimes you can scan other numbers and they'll work. I can scan my Dominick's (Safeway) card at Jewel-Osco (Albertson's) and it'll work.