Sigh ... I just can't bring myself to scape my Rittergrip across a chunk of carbide.

My advice would be to go with something more like the 'Gatco Micro-X Pocket Sharpener', which has two sets (fine & medium) of small ceramic rods that snap into a holder in an X fashion.

One thing to keep in mind is that the angle is fixed, so it may not exactly match the grind of some knives. For example the Ritterrgrips have a 15 degree grind. Still, if you really need field sharpening, this would do well.

Here is a link: http://www.campmor.com/outdoor/gear/Product___29240

Ken