I would strongly advise not to add any solvents to your gasoline.

First, the elastomers used in the fuel system are designed for commercially regulated gasoline blends. For instance E85 capability [85% ethanol] requires different materials; even the copper commutator on the fuel pump can't be used. Other organic solvents such as toluene, acetone are very strong and can adversely affect rubbers and plastics compounds that aren't intended.

Second, there may be coatings, materials, contaminants, gel-like substances, and other crud that quietly reside in the fuel tank that could be dissolved with an different solvent and sent through the remainder of the fuel delivery system with adverse effect. You may also help plug the fuel filters with this crud.

A bottle of dry gas (alcohol) is OK to absorb water but solvent concentrations beyond the normal gasoline blend may cause problems down the road.