macOS has keychains. Sometimes they’re a thing. When they are you might want to delete them. Let’s say you have an admin account. You want to keep the keychains for that account, but remove all the others. For this, you could do a shell operator to extglob. Or you could do a quick while loop as follows:
ls /Users | grep -v "admin" | while read USERNAME do; rm -Rf "/Users/$USERNAME/Library/Keychains/*" done;
If you borrow this, be careful.