Yeah nothing like animal waste on the poly pipe.....
The best thing to do is to get some bleach and rags and thoroughly wipe the pipe with rags soaked in bleach to kill the bacteria and then chlorinate the well when you're done.
Drop cable to me means the pump wire that runs down the hole to power the pump.
Never put rope in a well, if you don't trust the pipe, get better pipe.
Years ago there was a company that made poly pipe with 1/8" stainless steel aircraft cable bonded to it, that would be the only kind of cable I would ever consider using.