Summary of the idea from the link in the sibling comment, partially in the words of the author (edited by me):
[There might be] natural strains of SARS-CoV-2 in the world that have mutated to be non-pathogenic (asymptomatic), but are still infective and will provide immunity to the more pathogenic (deadly) strains.
[If there are and] we can find one of these non-pathogenic viral strains out in the wild we could [use it] much like the live attenuated (oral) polio vaccine.
I would add that the hypothesis can be checked very quickly and cheaply by genomic sequencing.
I can afford the cost of all the sequencing, what I need is access to a large number of samples from people infected with mild cases of COVID-19. My best estimate is you would need to look at north of 5000 samples to find a strain with the right sort of gene deletion.
[There might be] natural strains of SARS-CoV-2 in the world that have mutated to be non-pathogenic (asymptomatic), but are still infective and will provide immunity to the more pathogenic (deadly) strains.
[If there are and] we can find one of these non-pathogenic viral strains out in the wild we could [use it] much like the live attenuated (oral) polio vaccine.
The submitter seeks help to test this hypothesis.