To go a bit further then JEFF
summarizes, think of a strop as a high grit stone because that is effectively what it is. The 1.5µ abrasive I linked to is basically a 10,000 grit stone, and the naked leather refines further with a crisp polish.
Utilizing a strop is analogous to Westerners using a honing steel. In the context of hard steel like Japanese knives use, their steels are harder than these rods so they are not effected by them, and in examples such as ceramic or borosilicate of which are hard enough to effect them, typically they offer no higher than a 1200 grit finish which can eliminate a 5k polish in two passes. The margin for error to not degrade an edge is much smaller with rods as the potential to roll an edge or to hone at inconsistent angles amid the pass is exponentially higher than with a bench strop. Using a strop will refresh the edge of the edge very quickly & efficiently as they are used dry with little setup required & effectively no break down or clean up.
In reply to your question, application of more abrasive to the substrate will vary, but one application per 10 stroppings might even be overkill... reapply when it loses efficacy. Utilizing a strop will noticeably extend the amount of time between sharpening, as well.
Another method to refresh your edge w/o a full sharpening is to strop on the 5k stone I referred. This is very effective, but requires soaking a stone which can be a hassle to schedule appropriately. I suggested the strop set because of this benefit, and for the fact it includes a lapping plate, as well. I really hooked you up for the long haul.
Yet another method is to strop on newsprint. You can wet, not necessarily soak, your stone, and fold some newspaper around it. Believe it or not... it works. This would be a budget minded option.
As for JEFF's
suggestion, I think he meant this set.<--link