To maintain the edge on your straight razor, try these strop pastes from Herold. They are equivalent to black and green polishing rouge- the same compound used to polish steel during razor restoration work. By applying this paste to the canvas side of your hanging strop, you can "polish" the edge and  keep it lasting longer. Your edge will stay sharper in between honings and you should generally have a better overall shaving experience. Be sure to use light pressure and perform 25-50 laps on the coated canvas before going to the leather side. 

 
Green Chromium Oxide 1/2 Micron 15,000-20,000 grit

Black 1-2 microns 9,000-14,000 Grit

For more instructions read this post on Straight Razor Place: Pasted Strops a Rough Guide