You need similarly low amount of ClO2 to kill them buggers, even after intake, when they already party on your mucus membranes.

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The oxidising properties and the radical nature of Chlorine Dioxide make it an excellent virucidal and bactericidal agent in a large pH range.
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Data are available for chlorine dioxide that support manufacturers’ bactericidal, fungicidal, sporicidal, tuberculocidal, and virucidal label claims.
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Chlorine dioxide is registered with EPA (Registration No. 74986-1), and is considered an excellent bactericide, fungicide and antimicrobial agent. It has passed the EPA’s stringent DIS/TISS guidelines for use as a disinfectant and as a food-contact surface sanitizer.
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Chlorine Dioxide Is a Size-Selective Antimicrobial Agent