brake cleaner, the spray straw helps eliminate the rag and screwdriver, spray shake repeat....

Diesel fuel. Pinch off the hose and remove the reservoir, put in a shot or 2 of diesel, let it soak. Put a rag or shop paper towel in there and use a screwdriver to swish it around and soak up the gunk. It is better to disconnect the hose if you can get it off w/o breaking the fitting.