Petzl limice sharpening tool

Hi
I'm trying to work out how to use this. On the box the instruction is

In the instruction sheet inside it says


So which is it? Back and forth, or one direction. I was taught to one use files in one direction. However are they really suggesting one removes the screw to return the jig with each stroke?  And why place contradictory diagram on the box? In the written instructions it says only sharpen in one direction. So I thought I'd check online for a video:

https://www.youtube.com/watch?v=cpplVGC5ETs

clearly back and forth, and I assume wrong?

Thanks for any tips

Use the tool only if it is still yellow.   Once it turns black, it should be retired.  ;-)

They're not contradictory. Look at the orientation of the sharpening device.

Pat Light wrote:

Yep. I read that, but do people really unscrew the ice screw with each stroke. And I then can't understand the first illustration - what is it trying to say?

Aaron Liebling wrote: They're not contradictory. Look at the orientation of the sharpening device.

You have lost me there. It seems to be at one end in one, and the other end in the other. But it moves from one end to other with every stroke - so what are the two illustrations trying to say? What should I do and what should I not do?

Aaron Liebling wrote: They're not contradictory. Look at the orientation of the sharpening device.

This

"I was taught to one use files in one direction."

and this.

Files you go sharp edge to back. Back to edge fills the teeth of the file with metal faster.

If that sharpener uses a stone instead of a file you could go back and forth.

Seems clear from the petzl website: 

Maybe your technical notice is an older one?

Especially for non petzl screws, I was finding you have to go both directions initially in order keep the slide from seizing up from too much file engagement if that makes sense.