Gas tank cleanout

[nipper]

I am fixing up my 1985 Formula, probably to sell it. It has not been run in 4 years. I drained all of the gas from the tank today. There is no access hatch to get to the gas tank. Only way to remove it would be to cut a hold in the floor or remove the engine, and I am not going to do either.

Is there any kind of product I can or should put in the tank to clean it out? I am pretty sure I got out all of the old gas because I filled the tank before putting it to bed for its 4 year nap, and I got out right at the 40 gallon capacity of the tank. Put all of that gas in a buddy's big 500 gallon tank he uses for his equipment. Almost made me cry to give away almost $150 worth of gas.

[spareparts]

put some fresh gas back in, just 5-10 galons, tow it arund and get the gas sloshing all aorund, let it sit for a few days, then tow it around again. then pump that out and give it to your neighbor