How do you get back to your initial anchor to begin cleaning the pitch you just finished leading? And, how does one haul in this situation?

After a long traversing pitch (or overhanging for that matter) while roped soloing, you follow the same steps you would for a plum vertical pitch (arrive at the top point and build a multi-directional anchor, set-up your hauling system, fix the rappel line and lead line, yada yada). . . rappel the length of the pitch but instead of trying to swing back to your anchor, simply lower yourself about 15-20 ft (+ or - depending on the pitch) beyond the lower anchor point and then ascend the rappel line back to your lower anchor (remember, you fixed one end of the lead line and rappel line to the lower multi-directional anchor before you blasted off, eh?)

Once you arrive at the lower anchor you can lower the pigs out with excess tag line, a seperate lower out line, or whatever system you choose to get the bags off the anchor (For big traverses the tag line works perfectly, but I usually use a 30 ft 7mm cord with a load-releasable knot [learn the Mariners or Munter-mule overhand] to anchor the pigs so that the lower out is already set-up and ready). So, now you have successfully lowered out your bags so that 100% of the weight is on the hauling system on the top anchor (which you pulled the excess line out of and neatly stacked out of the way) You can now break down the lower anchor and begin to clean the pitch (most likely, since its a traversing pitch, you're using a 4:1 lower out, [check out this great short instructional video from Erik Sloan

Back clean as much of the pitch as possible and just use lower out points that make sense and can be left, Yeah your gonna do a bit of lowering out and reascending, Lots of work,

Or just bring a partner and get back home quicker

If you didn't back clean while traversing sometimes I think it is just as fast to re-aid while cleaning. Especially if the traverse is long and not gaining any height.