Getting Started with Clay: Questions on Salesforce Tech Stacks

Hi all, just getting started using Clay this week and have a couple of basic questions. I'm looking to create a list of companies in a specific industry that utilize Salesforce products. I have a list of about 800 companies and I want to run a waterfall to find out if Salesforce is being used and if so, which specific product is it. I've tried running the Full Tech Stack Waterfall which works to a degree but the problem is that if Salesforce isn't a part of the stack it spits out whatever other tech is utilized at that company. I want to set it up to where it just remains blank (or whatever best practice would be) if Salesforce isn't in the tech stack. I'm also curious to learn what is best practice for going on to run the same Waterfall for the rest of the 800 ? Should I continue to run it 10 at a time or just commit and run it across all of the companies on the list? Once I have this enhancement down, I'll only want to find people at the companies that use Salesforce products. TLDR:

Thank you in advance 🙏