A cheaper alternative to PBW is the Sun Oxygen Cleaner at the Dollar Store, just rinse well with plain water before using the Sanitizer. It works great on a brew kettle if left to soak overnight. One thing to be careful is if you have any poycorbonate (common in sight tubes), as they should not be left soaking in any oxygen cleaner. I use PBW after brewing on all my hoses and pumps but leave anything with cooked on stuff overnight and it cleans like a dream the next morning. You can also use Oxiclean Versitale Fresh but the Sun is cheaper and the same thing. Brewing is not over until everything is clean or soaking.
I only use Star San as a sanitizer. Follow this rule:
3. Star San
in other words Sanitize, Sanitize,Sanitize