First off, look at the lengths we go through on this site to keep equipment from running lean. Now you repeatedly want to run the leanest mixture possible that will still run? It may not score a cylinder, but it certainly isn't helping bearings. Leaving fuel lines and carbs empty after running ethanol fuel is even worse than leaving ethanol fuel in them for a period of a month or two. Good two stroke oils have a fuel stabilizer in them and leaving them empty will cause them to harden even faster. If you must, you'd be much further ahead to dump the ethanol fuel out and fill with something like trufuel. Or even better, dump the fuel out and run a fogging oil through.