I've been sewing since I was a teenager in 4-H--more years than I care to admit! And it wasn't until just within the past year that I learned what that little 'wad' is for on the long end of a seam ripper. Leave the piece as is (not pressed open), insert the long end into the seam so the stitching is between the 2 sides of the ripper next to the cutting edge and away you go. That little 'wad' is for keeping the ripper right there in the stitching line and you can unsew in a lot shorter time. So far I've had no problem with it nipping the fabric but I'm careful, too. Sorry this isn't a better explanation of how to do it but that little piece of plastic on the one side of the ripper is there with a purpose in mind! (This idea has been around for a long time apparently, just like the tabs in the end of the aluminum foil box--didn't know it was there for a reason!)