Do I need it? What brand and grit? I'm not a knife maker. Just a few hunting and kitchen knives. Thanks for y'alls experience.

BP...

Green compound works for me doing touchups.

I use Semi Chrome impregnated in a thick strip of leather.
Put leather in micro wave for a couple seconds to warm it up.
Rub in the compound and let it cool and dry.

CBN works for me.

What steel?

Most are carbon. I have a couple of stainless folding knives.

BP...

I use three, the black, white and green. I got them from Stropman