Years ago one of our local club members designed, manufactured and sold a product he called "Reef Gadget". It was simple and elegant and made with a piece of acrylic that was bent, and an off-the-shelf scraper was attached with nylon bolts. You'd use superglue and glue this to your MAG Float. It came with a plastic razor blade and metal one....single edge standard blade. Here's a picture of the one I have:
Now this one is no longer being made, but there is one that's very similar that is now being sold.
You can use a similar design, but with a wider blade portion.