First pass metabolism, or just absorbed by mucous membranes of the mouth, blood flow isn’t great so absorption is less systemic, just mess up your mouth and throat a bit really, but might help some symptoms locally.

The nasal dose is low compared to oral and those dissolve in areas with high blood uptake.

Is this the next tiktok challenge?

They get destroyed by stomach acids and saliva enzymes. Unlikely to even make it towards First pass.