May be a much cheaper and simpler solution than heating. Keep the fuel moving. If it is flowing right along, there is a pretty good chance that it isn't going to have time to build up on a decently smooth hunk of fuel line. How much flow rate you would need and how much good it would do are calculable.
Someone mentioned that the HP pump is a nice inefficient hydraulic design where it is always making lots of flow at full pressure, and the excess fuel is recirculated back to the pump inlet. Add some hose and recirculate it back to a jet in the tank directed at the suction inlet strainer. Or even to a T in the inlet strainer assembly. Or point it at the tank sump and let it mix with any water present. Whatever the CFD analysis indicates if the best point to inject the recycled flow. (And the HP pump outlet flow is going to be warmer than the inlet feed by some amount, so you will get some minimal fuel heating.)