If you got hard water and there's lime or scale buildup I'd use an acid-based cleaner instead. I had turtles for years, so scale and lime were the biggest obstacle to getting their tanks clean.
Soaps actually reduce bleach's killing power somewhat, but if you only add a drop, it will be easier to apply. Just don't add too much or it will leave a residue.
Also, allow enough contact time.
Don't even bother with anti-bacterial soaps, as people don't give the soaps enough time to do their jobs, and the bacti that survive pass their immunities onto their progeny.
Why haven't bacteria adapted to the agents found in bleach, alcohol and lemon juice? The reason why bacteria aren't resistant to these agents is because they do not leave a residue. There is no chance for surviving bacteria to adapt within the residual environment, so bacteria are just as susceptible to bleach and alcohol as they were 100 years ago. Skip the antimicrobial smart bomb and go for the big bleach blockbuster.