How long it takes till you need to refresh it depends on a number of factors including the coarseness of your beard, the fineness of the edge, your stropping technique, and how often you shave. An edge can last a few weeks if finished to .25 micron or .1 micron diamond paste or a few months if finished on a stone. I have heard that using newspaper as a strop can help refresh the edge just as a pasted strop will. I would say for now just get the regular strop and you will be fine. A linnen strops usefulness is debated by many but I love it and use it. It is slightly abrasive especially if pasted with white paste. Mine has been slowly darkening from the metal it removes from dozens or razors so it is a very gentle abrasive (talc I think) but it is supposed to help maintain the edge even longer.