Applying an substance externally VS smoking it is very different.
I would be lead to believe that you have a smoking addiction and are seeking excuses to justify it.
Personally I use H2O2 (Hydrogen-Peroxid) 1.5% in a mister sprayer and spray (through the mouth) as I inhail - good for sinuses as well but sensitive, just don't get carried away...
BUT a word of caution. It will break up the toxins and stuff. Be VERY careful starting out or you could make yourself sick.
I do it when ever I feel alerigies or a cold comming on. It is safe to do 3-4 times a day once you have cleared all the lung build up out from smoking....