Tips for Excluding Clients in Company Search with Clay

Hey guys 👋 Im hoping some of the clay power users can advice me on this. I have a client that has over 9K existing clients that we want to exlculde them out in the company search so we can determine other prospects . I know there is no “exclude company” filter so its a bit of tricky condition. What do you recommend to do if you wish to filter out companies that you dont want to contact when you are building a list so we dont waste more credits?