When you have done a particularly good job at cleaning up a column using Cluster + Edit, consider creating a master-lookup table with those results.
|Step 1: Add a Column > Duplicate to your project at a step before any changes are done to the column.|
Step 2: Keep all the existing steps used to clean up the column.
Step 3: Add a lens to your project containing only the original and clean version of the column.
Next time, you can use the AnswerSet from that lens as lookup table and be assured than new data is conformed to the same values.