Similar to JMTIRE's solution.
We have quick disconnects on the main line, we just disconnect and poor mineral spirits in the line while spinnig the motor over (ing. off) untill the mineral spirits come thru the injectors maybe 10 seonds longer. That coats the injection system and the cylinders and will last forever. In fact it's a good way to store over winter. Ready to go again the alcohol washes the mineral spirits out and fires right up. Mineral spirits is a lot cheaper than WD-40, like $6.00/$8.00 a gal. at the hardware store.
JMO
Zip.