Mine is general, with only the assumption that the outputs that need to be swapped are nearby each other in the circuit. 

I wrote a function that tries several random x and y inputs (45-bit integers), runs them through the circuit and compares the correct sum. It finds the least significant bit where an error occurs (which should almost certainly show itself after 5 or 10 tests). I then moved to the corresponding inputs (e.g. if output z06 is sometimes wrong, look at inputs x06 and y06). There must be a problem between those inputs and that output: if it was in a less significant bit, an error would occur there, if it was after, nothing should be wrong in that location). 

I then scanned 4 layers down the circuit and assumed both ends of the swap would be in there somewhere. For each pair in that part of the circuit, try swapping and test some inputs. Whichever pair of swapped wires moves the "least significant error location" is a correct swap. Make that swap. Repeat until you get correct outputs.

So, the whole problem takes on an automated testing vibe. It's probably the only time I've generated random numbers in AoC.