I once used [no] Lucas UCL, and drove my Corolla with it's perfectly running engine but swiss-cheese body to the bone yard at 213,000 miles. In fact, my father before me also uses [no] Lucas UCL, and he's at 287,000 miles in his 1996 Camry. These weren't magical Toyotas either, they were the made in the USA ones, with PYB OCI's every 10,000 miles ~ ish.
So, using the same logic as TCW3/UCL proponents do, these cars never would have gotten this far had we used it... thank god we didn't.
Sorry if that's too close to trolling. Chalk me up as "not", and the stories are real.