Propane (or natural gas) might be a better answer here if a propane conversion kit is available for your generator engine or if piped NG is on your property.

Failing that, buying aviation gasoline (whether 92UL or 100LL) or using gasoline unpolluted with ethanol, a gasoline stabilizer, and exercising the generator for 2 minutes every half-year is probably time and money savings over cleaning the carb.

Cleaning the carb is also an easy sub-15 minute task from tool drawer open to tool drawer shut the second time you've done it. Give yourself an hour the first time maybe. A bottle of spray carb cleaner will last you a decade in all likelihood. I go through this every other year or so with seasonal equipment (lawnmower and snowblower) and it's easier to clean the carb when needed than to chase down and keep avgas on hand.