Sanitizing data is necessary — but over-filtering makes it 'clean' to the point of deleting the data you needed. The line between removing noise and erasing content can be thin.
How clean is clean enough?
Each pass strips one more character class; stacked together, even valid strings vanish. Keep the meaningful part rather than filtering until nothing remains.
About this piece: an entertainment comic by DETOON (Rocco and Leo), just for laughs — not a data-processing guide.