I stopped using the stuff 21 years ago when it fouled a spark plug in a 4-cylinder motorcycle I was trying to sell. I found just shutting the fuel switch off and running the carbs dry (or draining them if accessible) worked every bit as well. But for diaphragm carburetors, I was always better off just leaving the fuel in them. My weedwhacker, saw, and paramotor used to start right up every spring using E10 with no additives. The key is making sure caps are tight, not only on your fuel cans, but also on the equipment fuel tanks. E10 gas can last up to a year if you can store it air tight.
Now I just use E0 in everything, and don't have to worry. My saw started 18 months after its last use. Took a few pulls, but once it fired it ran fine. The more you use your equipment, the less need there is for additives. Waste of money if you're constantly using the fuel, IMO.