A frequency is what does work. Whether this frequency is a killing frequency or healing frequency really depends on what it resonates with.
Even if you were to find and isolate a healing only frequency (one that entrains and does not resonate with anything else), if you do not use it with just a sine wave, you will produce harmonics that will most likely resonate with something else.
Since Rife is a killing modality first and foremost, you would be hard pressed to keep it isolated to only entrainment frequencies.
I do not think that it would be easy to do what you wish without extensive research as even the best of the healing modalities seem to have frequencies that also are used in killing modalities.
I do not think anyone took the time to try and separate each frequency out into one camp or the other.
Even the normalize sets use killing frequencies to remove the source of problems that lead the system/organ into less than ideal health.
I would also caution you not to run the immune system programs as this would invoke the body's own natural killing mechanism.
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