An even faster way (mouse only) to check a column for any false entries while cleaning (1:39:06) is to just turn on auto filter. Clicking the filter arrow for the TRUE/FALSE column will show you the values found in that column at a glance and will not show duplicates. Don't see FALSE? You're good. Turn off the filter. See FALSE? Then select it so you only see the ones that are FALSE which will help you quickly identify the pattern that caused it to fail.
An even faster way (mouse only) to check a column for any false entries while cleaning (1:39:06) is to just turn on auto filter. Clicking the filter arrow for the TRUE/FALSE column will show you the values found in that column at a glance and will not show duplicates. Don't see FALSE? You're good. Turn off the filter. See FALSE? Then select it so you only see the ones that are FALSE which will help you quickly identify the pattern that caused it to fail.