So, I do maintenance once a week, and one of the things I always let slide was flaking out the climbing rope and getting all the chips/bark/dust off and out of the bag. Ended up pushing it off a little too long, so finally got to it tonight:
Not too bad, we can still see the stitches of the bottom.
Time to time, I blow the chips directly from the chipper into the back of my van. Even if I put a tarp all around the sides, all my gear stored there looks pretty much like the bottom of your bag. Of course I find rarely the time to clean the mess.