Re: Ethanol
Throw a little SeaFoam in it.
(edit) Of course that's a joke. SeaFoam is mostly alcohol.
The primary problem is not the fuel, but you're getting water in it, maybe by flooding the fuel vent in rough water, maybe by buying bad fuel. Maybe rain water in a poor filler or vent.
If you have all dino fuel, and you get 4 oz of water in it, the water separator sorts it out and it's a minor maintenance item. If you get 4 oz of water in a tank full of gasohol, it drops out a couple of quarts of chit that overwhelms the separator.
If you can't buy non-alcohol fuel, maybe your best effort would be to figure out the water intrusion problem.