Have used Starsan for over 30 batches of beer - zero contamination issues.
Mix exactly as directed (close as possible) - I forget what the amount is for 5 gal but on brew day I use half that amount into 2.5gal in a clean 5gal plastic bucket (buy one and a lid at your local home improvement store). Mix it up pop the lid on and you have a "sanitizer chamber".
Also buy a quality 16oz spray bottle - fill it from the mix you just made. Now you have a spray on sanitizer. Wash and rinse things well (rinsing is equally important) then sanitize before use.
Waiting for 1 or 2 minutes is a Fed Standard for commercial operations etc. (Cleaning a 300gal tank) - wet the surface well let sit for 10-20 sec and you are good to go. And it is a true no rinse sanitizer --- its not a soap but just a solution at a ph of 3. Drain or shake off any excess and proceed.
I tried the iodine stuff -- and lets not even think about bleach --- starsan is as easy as it gets .... and I'm freakin' lazy