The actual ozone output from these other less expensive units are about 50 mg/Hr, and not the claimed 200 mg/Hr. I know because I have tested them with a Genetically-Modified Anceros Model 5000 ozone in air alayzer. That is why it would take "months" for you to ozonate Olive oil.
Also, the less expensive ozonators use plastics in the ozone path. The latest SOTA WOZ5 uses pure Quartz Glass and surgical grade Stainless Steel. These are very high quality, near-medical grade parts. The ozone produced is very pure and "sweet".