Is there any point in sifting the semantic core for contextual advertising on the words "!dummy"?

Question

contextual advertising

Hello fellow marketers and contextual advertising specialists.
The essence of the question is that a small semantic core is being assembled, for example, for 2000 phrases (raw, with all the garbage). Does it make sense to spend time manually working through all 2000 lines, identifying garbage and relevant phrases? After all, you can simply collect the frequency by phrase matching (“! Phrase”) and if there are less than 1-2 impressions, then immediately it is in the trash and then sift through the remaining phrases? Out of 2000 phrases, about 400 remain, which simplifies work and reduces time.
Is there any usefulness for contextual advertising of a phrase with zero impressions in a phrase match?
Thanks in advance for taking the time to answer my question.

Answer 1

And I would leave blanks. Now there may be no requests, but then they may appear (especially if the request may have seasonality), and you already have a key in work, get a cheap click.

Answer 2

This is how empty queries are filtered out, but it is better to do the main check in phrase matching and the additional check in exact match. Otherwise, you can exclude a keyword for which there are no queries with one "!ending", but another "!ending" is effective.