Depending on the rods you may well be able to keep them clean with a pencil eraser. That's what I use
50 is a bit excessive mate, you should get result's with about 20 stokes on each stone, and about 10 for touch up's on the fine rods
Comet works great , great tool , be carefull around acute points . The only drawback , they aren't good on serated . Chris
The sharpener is my first ever dive in to knife sharpening so I have nothing to compare it to. I like it a lot and it works well and is simple for me to use. It gets the job done and fast. I can certainly recommend it.