EDIT: Also MAN the wall of flesh is rough even with two people. I'm not sure how much better we can get at this frankly. We usually die before we hit the end of the highway. Also incidentally you can now forge hellfire arrows.
So yeah, I soloed the lil' (well, big) bastard. Suggestions: The runway is obvious, of course. The solo one I had ate up probably 500-600 blocks of mixed imported materials, one tile tall, plus a fair amount more paving over open lava pits. Fairly sure it ended up being >1/2 the length of the map (and I ran out of damn room before I killed it).
Make sure to light it up well -- some of the things it's going to be throwing at you are pretty hard to see. Clear overhead obstructions as possible, you'll want plenty of space to throw things at it.
Full molten, with as much defense accessories as you can stand to load up -- you
need to be taking as low a damage as possible from the eyelasers, because you're not going to be dodging much of them. You might be able to get away with shadow or necro, but I wouldn't recommend it.
Combat frakking drugs. Ironskin,
regen, bowl of soup. Obskin potion, just in case. Possibly magic power or archery depending on what you're attacking with. Anything else you've got lying around, except probably featherfall. Don't get drunk for it -- you don't need the defense drop. Obviously use the best healing potions you have.
Weapon-wise, I did it with mixed flamarang and sunfury. High damage/attack speed and/or multiple hit is
very nice basically requisite, at least in the early stages of the fight.
As for the fight itself. Kill the hungers, or at least all the ones you can reach, before you do much damage to the eye. The hungers will fooking murder you.
Watch out for the leeches, as they hurt like a bitch and are very hard to see, as well as being small and fairly quick. The leeches will fooking murder you if you don't stay as far off the ground as you can manage, while keeping your speed up -- you'll be jumping a lot, honestly. Rocket boots help there, to keep off the ground for a bit. Killing the leeches is something you're going to do incidentally, honestly. Otherwise you're going to run out of
time space.
Once you've got the not-the-eyes killed, start murdering on the eyes. You're going to need hermes (or, even better, spectre) boots to keep ahead of it once its hp gets lower, as it gets faster (both in movement speed and laser pewpew) the more damage it's taken. If you can stay ahead of it, and have high enough defense, once you've reached this point it's just a matter of whittling it down (8k hp, fairly solid defense) while tanking the lasers.
The lasers are the least threatening thing about the wall. If you've got molten/ironskin/regen, you can mostly ignore them.