Rule 1:

Turn it on 24/7. It’s designed to be “always-on”.
No worries, it uses less than 6.5 watts/hour.

Rule 2:

Shut all doors and windows.
Treat it like your “fresh-air” producer.
You don’t want you “fresh-air” to escape.

Rule 3:

No air fresheners and fragrances. Remove them.
They add on to the “workload” to be sterilized.
You will experience “Medklinn fresh-air” soon.