Your absurdist attempts aside, the important thing to consider with a prophylactic medication is the therapeutic index.

Let’s take vaccines. Covid itself has a risk of harm of around 1:100 for older age groups of requiring hospitalisation. Risk of harm for vaccines is established at around 1:200,000.

Ivermectin? There is no good data on the therapeutic index however it is a toxic substance with a low therapeutic index and a narrow therapeutic window.

The sensible thing given the available data is to encourage vaccination. Barring that, masks and social distancing. And of course there are places where both there is no vaccine supply, and social distancing is economically in feasible. Is this a use case for ivermectin? Most data says no because establishing TI and TW and ensuring adequate safety of dosing is logistically about as difficult as maintaining social distancing.

Good chat