Charged leather is a strop that has a fine cutting/polishing compound rubbed into it. Many compounds work.
The most common is green compound such as at Lee Valley. http://www.leevalley.com/wood/page.a...84&cat=1,43072
You prep the leather with a solid fat, tallow being ideal. Then you rub the compound on, it doesn't take much. Spread it out as best you can with your hand.The heat and friction from your hand help it dissolve into the strop. And you're ready to strop.
But many metal polishes work. Flitz isn't bad but dries out quickly. I've used some Flitz and some strips of cardboard as disposable strops and been satisfied but it's a very fine polishing compound so your blade had better be pretty dang sharp to start with or you'll take forever to refine the edge.
I have a strop from Lee Valley too. It's well made but you have to be careful in it's use as its easy to chop up the leather strip with the very sharp knives you're stropping. I've got a couple of gouges and chamfered edges in my strop as a result of a few slips.
Mike Stewart has two compounds he uses to finish sharpening knives. His are Black and Green. The Black is referred to as Black Magic because it can produce a thoroughly wicked edge. His Green is just a polishing compound and will not hone. My neighbor has some of this too but I haven't tried it. I do have some of Mike Stewart's outdoor knives and they are the sharpest things I've handled out of the box. I can keep them scary sharp but not as sharp as shipped from Mike.
You can sharpen knives from dull with a stropping technique too which uses wet/dry sandpaper (the kind used for sanding metal). Home improvement stores carry some of this but you'll have more choices at an auto parts store like Pep Boys. This produces the convex edge. Some good instructions on Mike's site are Bark River Collectors Association Convex Guide
When he says a 'hard' mousepad he means HARD. It should have just a little give, more resiliency than give, like leather does.
this technique is fairly inexpensive to get into but you'll consume sandpaper every sharpening session.
Start with about 400 grit and work your way on up to 2000 grit. You'll commonly find grits at 400, 600, 800,1000, 1500, 2000. I usually skip 600. Depending how dull the blad is, I start resharpening at different higher grits.