Well, for that kind of manual data editing and cleaning-up (as in "I don't know what I have to change untill I see it") spreadsheet is pretty handy. However, a decent database front end is much better. Here you can still do manual changes, but for anything involving more that a row or two you write an SQL one-liner instead. I usually end up using combination of SQL and 'visual inspection' to find inconsistencies, but mostly SQL to fix them. (The tasks were similar to yours, albait in different 'domain' - once is was food safety lab parameters (kind of sample, lab, what is measured, method, instrument, limits, units etc), the other parameters defining retail banking products). That was not fun