+1 I learned from the Mexicans that clear brush faster than a weed whacker that you gotta keep the blade sharp. Keep a file in your back pocket as ya cut and sharpen as soon as it starts to get dull. You draw file it down both sides of the blade being careful not to slip and cut off a finger.I like using a file on a machete. It will sharpen it quick!
I use a bottom of a coffee mug for my knives, same idea. In the field I just use a rock.in a pinch, you can use the back side of your common every day dinner plates. The little raised edges that the plate actually sets on does a fine job sharpening almost any sort of cutlery in a pinch.
A chef friend once taught me that. Something about plates being made out of, or containing porcelain or ceramic or something or other.