I have an older Blichmann 7.5gal. I only take it apart about every 6 brews. I soak with very hot water and PBW and then recirculate with a pump through both ports. Cleans up very nicely. I have never had an infected batch.
I take my Blichmann apart every time valves and all. Why would I want to spend 30+ dollars on ingredients plus all my time for a what if? Yes a pain in the ass but I sleep better at night.
I have a cheap conical with non sanitary fittings and I put boiling water into it up to the the lowest threaded fitting, which takes 2 gallons for mine.