1996 Dodge Avenger Reguarding the fuel system.

I have a car that's been sitting for awhile and wasn't starting after many attemps. Docfixit gave me some very good advice, he told me to check to see if the fuel pump was clogged because of the fuel breaking down. It was.

I have purchased a new fuel pump, fuel filter and fuel pressure regulator that I will be installing here shortly.

As far as my questions go.

How likely is it that the fuel lines need to be replaced as well? I didn't really find that much residue in the hoses or lines from the fuel sending unit that holds the pump in place. What very little I did find was cleaned out using q-tips.

Anyone have any idea how to clean the gunk out of the fuel tank? I'm going to try to use a pressure washer and let the tank just dry out in the hot Florida sun. Is there something I can add to the tank to break down the gunk before I pressure wash it though?