Optimizing Clay Searches to Avoid Duplication in Lookalikes

Question: I'm using Clay to find lookalikes, but I want to ensure that the companies and people from my current search aren’t duplicates of what Clay has found in previous searches. What’s the best way to set this up? Should I consolidate all the companies in a table and have Clay check before enriching? My list is over 19k companies, so I’m concerned about time and credit efficiency. Any suggestions? Same question for people BTW, do I need to consolidate all the people already found into a single table and have it checked for duplicates before proceeding? The number will be 1:1 to 1:5 for companies BTW so the numbers can get large quickly..... TIA