In general, you should keep running water and the disposal for at least 10 seconds after it sounds like all the stuff you are disposing has gone through to rinse things clear. If you have not been doing that, that may help. Depending what your dishwasher is putting out, debris may be piling up against the grinder screens, especially if you use the disposal infrequently, since "the clog always clears up in less than a second of running the disposal."
Run the disposal when the dishwasher is draining - not "for just a second" - through the whole drain cycle (run hot water into the sink as well) to help clear it out. Not the whole wash cycle, just when the dishwasher is pumping out. The extra volume and dishwasher detergent should help clear things up.
In a different direction (can be noisy) run cold water, fire up the disposal, and dump in ice cubes - which can help to clear build-up off the blades and mechanically clean things up.
If you'd rather not get into tearing it apart (or you'd like to exhaust all avenues before you do) a third option is to plug the drain, run the sink full of hot water, and dissolve a good bit of baking soda in the water, then unplug & run that through and let it sit, without rinsing or running more water for several hours or overnight. The less hazardous end of drain chemicals...turns grease to soap. But so does most dishwasher detergent, so it may not do much more than the first approach.