Hi Christine! Thank you for the kind words about the podcast :)
We're currently determining how we can surface subscribers who haven't clicked in order for you to clean these subscribers from your list. At the moment, the only way you'd be able to implement this on your own is if you always tagged every link in your email with a tag like "has clicked" so that every person who has clicked a link within a message is captured. Then you'd be able to create a segment of everyone who doesn't contain the "has clicked" tag.
This is definitely not an ideal solution so we will keep you posted with any product changes that we plan to make this process easier.