it is basically the same as I use for my glow engines.
my son and I raced go karts for several years, these engines are run on methanol and the typical procedure after race day was to drain the tank and then run the engine gas on gas for a few seconds. because the engines need 3 times the volume of gas to run on methanol, the jetting quickly flooded the engine, so the run was really wet and sloppy. the idea was to contaminate all the alcohol and flush it out of the fuel system and carb. after that, a fog of Marvel Mystery Oil was sprayed into the plug hole and the engine pulled over a few times for storage during the week. alcohol evaporates quickly and leaves a white residue that plugs jetting and passages in the carb. the gas prevented this from happening and the MMO protected the cast iron sleeve and rings from rusting because alcohol has a lot of water in it.
it is a good idea to treat any engine that runs on regular gas the same way for any storage duration. today's gas with 10% alcohol is garbage . it has no upper cylinder lubricant in it at all, anymore, as well,... so adding a little MMO to a full tank is not a bad idea for all your small 4cycle engines.
this might sound extreme to some people, but the kart engines we ran cost $1000 each so a new plug and a little time at the end of the race day, was well worth it.