this is what we have been doing for the last 18 years after every race event, and never had a problem with nozzles, etc; drain the fuel tank, and fuel line from tank to fuel pump, blow it out and let air dry until getting ready for next event, blow out fuel pump, clean with brake clean blow-out again and put Marvel Mystery oil turn over by hand and put it a plastic bag, blow out fuel shut off , brake clean, plastic bag, take out the fuel nozzles, blow out, clean with brake clean wrap in plastic bags, blow out clean with brake clean barrel valve and wrap the nozzle hose ends in plastic. This what has been recomended when we 1'st started racing the JF car by Bob McKray, race engine builder, engine builder and tuner for Don Enriquez Jrfueler, Don still works for Hilborn, and also recomends this cleaning process and Gene Adams, who now flows and sets-up fuel systems after working for Hilborn.
Mike this might be more or less work or time than your 70-30% gas/oil, but we have never had a pluged nozzle, because of the corrosion that can happen with alky. I have helped crew on a comp racer for years and they would not use clean their fuel system, mostly because they raced often at Division and national events, so they would have little down time, BUT, would have crystals in the Kinsler nozzles from time to time.
We can't use WD-40, because it will cause the fuel to fail the fuel checks, as will top oiler, and alky with top oiler, like VP M-3, and of course VP M-5 that has nitro in it.
We also drain the engine oil and filter after each event, of course looking for metal, and also because alky attracts water, and you have alky in the oil from the rings, so we dont want a rusty iron block after sitting for awhile. BTW, don't leave alky jugs open,or fuel tanks, it attracts water.
I hope this helps guys
Jon