How is SDF more effective in treating cavities than ozone?
Ozone is a good way to kill bacteria, but it doesn’t harden residual decay left behind.  The statement that lesions must be decontaminated prior to restorations is not accurate.  This was proven repeatedly by the Hall Technique crown studies, and Dr. Edwina Kidd’s work in the 1990’s, again by Dr. Tencate’s work, and then again by Dr. Chu’s and Dr. Geoff Knights work with SDF.  You simply need to have sound margins when the restoration is placed and the residual decay or carious material will die and arrest.
Ozone does kill bacteria, it is effective, but SDF does that and hardens residual decay. Regarding depth of penetration, many things affect that with both techniques.  Lesion size, severity, dryness, etc. It’s hard to say one is deeper than the other, but we do have data showing SDF penetrates 2.42mm into lesions.  Likely farther in some cases.