I would take it apart a little further rather than just spraying it off. You don't have to tear it down to the last tiny part like the Schwinn manual usually shows (they had to cover EVERYTHING). You should try to be sure everything is clean, and there is new lubrication on everything that moves. Draggy old scummy grease all has to go. I would get lubrication of some kind under the retarder springs even if you don't take them off. I don't remember that particulars for this hub, but you can probably just turn them like a spinning wheel would turn them. The planetary gears would no doubt like some fresh light grease or oil. Also there are loose balls in there between the two clutch drives, big ones like 1/4" or so, so not impossible to deal with, but disassemble it over a pan. Use grease to hold them in place while you reassemble.