I know there is a growing concern about all the Covid crisis going on and the mass hysteria of being safe rather than sorry, but most of the propaganda comes from paranoid parents who have been conditioned by the media to think that everything is a carrier of disease. Instead of getting into the politics and the spread of misinformation ( that would be a long rant), I'll get to the point.
Alcohol based sanitizers are for skin, bleach sanitizers are for surfaces. Bleach sanitizers are not for metal surfaces, as it will dry out the pores and leaves it susceptible to rust.
There have been ridiculous measures taken to "quarantine" mail and packages through the postal system for up to 2 weeks to make sure that things are "safe" to ship. This is nothing more than ignorance and political policy, and does nothing more than hold up the whole system.
Personally, I would spray the rifles down with WD-40, wipe them down good and let them set in the sun for a hour.