Minimum time for applying a specific frequency

I have seen where some users are trying frequencies for 5 minutes, others for only 1 minute in some cases. When observing under the microscope, some organisms are zapper in as little as 30 to 45 seconds at certain frequencies. Others that I have seen can take a good bit longer.

Occasionally, I see recommendations of 10 minutes or longer for certain frequencies in some cases.

What is the generally accepted minimum time for applying Rife frequencies and where is this published?