Potential to destroy viruses using prions?
Prions are misfolded "versions" of proteins already present in the genome. These tend to bind to their properly folded counterparts and catalyze their misfolding into prions. Although unlikely, it is not impossible to imagine that they might interact with other macromolecules. That being said, injecting a human with prionic particles for any reason (especially in a clinical trial for the common cold) is EXTREMELY unlikely. Even if you prove that it works in animal models, injecting a person would be considered too risky. Additionally, the "benefit" of that would be marginal - curing the common cold, from which > 99% of people recover even without any medication. Given that there is great risk and very little benefit, we will most likely never know for sure how feasible this is (at least for the common cold). As a concept, it could work, but would be extremely difficult to get right.