I looked at the website that sells the Fokin hoe. They give pretty straightforward directions on how to make a handle for it.
As far as how often to sharpen it, it merely says to keep it sharp--not very helpful. But given what the Fokin can do, and my experience
with other types of hoes and tools that cut into soil, I would have a sharpener/whetstone in my back pocket.
Hope that helps.
I would love to have one of these tools. It would make quick(er) work of preparing a new bed, or getting an existing, somewhat overgrown bed back into shape, making furrows, and cutting all those weed that grow in the corners where my lawn
mower can't reach. I bet it could even help me edge my beds while standing up, instead of having to crawl on all fours with a pair of scissors. Getting up from that position is the *real* problem!