I think nasal sprays are a more cost-effective solution.
Last I checked, the evidence for efficacy of nasal sprays was iffy (in part due to a paucity of unbiased studies and some questionable methodologies). I’m not opposed to the idea of using selected sprays on a very low risk of harm / uncertain benefit calculus, but—unless the evidence base is significantly better than I recall—then I think we should be careful to clarify that this intervention isn’t in the same evidentiary ballpark as the one OP recommends.
Last I checked, the evidence for efficacy of nasal sprays was iffy (in part due to a paucity of unbiased studies and some questionable methodologies). I’m not opposed to the idea of using selected sprays on a very low risk of harm / uncertain benefit calculus, but—unless the evidence base is significantly better than I recall—then I think we should be careful to clarify that this intervention isn’t in the same evidentiary ballpark as the one OP recommends.