What I have been doing for the past few months is eliminating references to "Y, Somme, Picardie, France" and writing in its place, ""Y" is always WRONG. Don't use it." This won't the correct the error already entered but it may prevent other people from copying it.
I have also been trying to eliminate obvious errors, i.e., relations listed with impossible dates, more that one person listed as a mother or father, parents with the same name and birth/death dates as the sibling, etc., as "conflicting" or "conflicting dates". This won't correct
the bad entries but may make new people cognizant of the problem.