This means that the MT has been diluted hundreds of thousands of times, and actually none of the original substance can be found. This causes a lot of the controversy. However, I think the molecular energy of the original substance, the vibrations, still exist. Besides choosing the correct, remedy, the simillimum, you must choose the best potency. Generally, the lower and medium potencies act better on acute symptoms of illness.
Higher potencies act on more profound illnesses and long term ailments.
In rehabilitation you will mostly concern yourself with the lower to middle potencies, 6x to 30c. But, the higher the potency you choose the more accurate you must be with your selection of remedy. Sometimes you may choose a remedy that is not the perfect choice. As a 6x potency you may get some results or improvement. As a 30c potency you may get no action.