Have a 2011 Elantra. After 7 yrs, washers have quit spraying. Can hear the pump motor running. From what I can learn, it appears that the bottom of the reservoir has an accumulation of gunk clogging up the filter and pump. I am ready to try to clean out the reservoir by siphoning and/or flushing with a hose. Can anyone suggest a mixture to put in which will dissolve the gunk? I'm thinking vinegar, baking soda, or combinations thereof. Any suggestions? At this point, I'm not ready to go to the trouble of removing the bumper to access the pump motor, without trying the above. Besides, even if I were to remove the pump and filter to clean, I would still be stuck with the gunk in the reservoir.