If you are treating with the appropriate water course medication that should be sufficient.
Dips are generally used when keeping the fish quarantined is impractical, large koi for example.
Personally I would run one course, make notes on type and its effects, document with pictures.
Go though the process of med removal and recovery phase.
Run course 2, repeat as above.
You can dip them but the stress of capture and dunk will add to the stress load, stress alone is a trigger for some infection and disease.
Research-Osmotic shock, temperature shock and pH shock.
Care should be taken when transferring from one medicated solution to another, previous post concerning toxicity of mixed medical solutions.