So you have got a super targeted group for "red widgets" and under "See search terms..." you notice that you have a hundred or more combinations from your broad match and modified broad match. Adding negatives can be a pain one by one and sifting through this list and copying and pasting one by one would also slow you down. Especially if you have tons of super targeted groups with this same problem.
So here is what you do. Change your date range to all time, and export the full keyword list within the group to Excel copy and paste this in your favorite text editor. Make sure it has a find and replace function. Can't use this method without.
1. Do a find and replace for "widgets" to "". Nothing.
2. Do a find and replace for "widget" to "". Nothing. Doing these both seperate and in this order will insure you catch all variations.
3. Do a find and replace for "red" to "". Nothing.
4. Do a find and reaplce for " " only this time replace with a carriage return. Now every single word has been seperated.
The list you now have back will still be pretty rough depending on your industry etc. I did a couple other find and replaces to clean up spacing and make this more legible. Find and replace for doubles spaces, multiple carriage returns to a a single and then again and again until everything single word was on its own line.
Go through this list manually removeing terms you know are good for your campaign. Everything else stays. Again depending on your industry some numbers, single numbers, or even single letters would even stay. Example: "c clamps" where you are selling another specific type of clamp. You will want the -c as a negative. So leave them in. Be sure to remove mispellings we like those.
After editing this list, check it again. Its a long list and it is easy using this method to leave in something that could potentially have unexpected results. Think about each word, spend the time now as opposed to one by one over time.
Once you are good with this list you are going to do one more find and replace for once again a carraige return to add the "-" in front of every term. Copy from your editor back into a new Excel file. Use the Data Filter Advanced option and check the "unique" check box. Copy this list back into your editor and review it one last time. Click Add Keyword option on your group and paste and save.
Monitor the performance very clsoely for the next couple days just to be sure you didn't add the wrong terms. In a week you should be able to come back to see your "See search terms..." and this list will be in much better shape.