Jungle Scout can help you find the keywords that are not performing well in your PPC campaigns, but are driving your PPC costs (above 100% in the last 30 days).
When the ACOS is high, our system will notify you about this in the Home Dashboard section.
What you can do from there is click on the "these keywords are most unprofitable" to view all the keywords and add them as a Negative Exact so this keyword is no longer targeted/active in your campaign: