alcohol evaporates fast, thankfully... i would add any more moisture to the problem.. as the moisture is the potential problem.
Once dry if they don't germinate all is well. I wouldn't worry too much after that. I OCD kicks in, a dry cloth might remove any residue left on surface. if it absorbs enough water, it'll germinate, so don't add more moisture.
Also, why spraying seeds with anything? Over-thinking it and manufacturing potential problems....
trying to remove organic bits for storage? Use a box with a slope.. seeds roll to bottom, flakey stuff stays at top.. remove, rotate, repeat a few times and it's clean enough for storage.