Snorting alcohol is definitely not recommended (apparently it is quite unpleasant), but yes there seem to be plenty of people who apply small amounts of liquid solution to their noses. So you can use liquid or solid carriers for insufflation. Again, there should be info in the 25C-NBOMe thread(s). The action of N-benzyl PEA compounds like these seem to be dependent on how quickly the drug it makes to the brain. The more acute the administration, absorption and transportation, the more severe the effects would be but that probably also includes side-effects and the type of danger that could kill a sensitive person.
So yes it would be effective, and you might lose less product than when taken sublingually / bucally, as long as your amount of carrier is not excessive as that would cause dripping out of the nose to either direction. But no, if NBOMe compounds are not particularly safe, this ROA probably is even less so.
I think the same reasoning holds for vaporizing / smoking NBOMe compounds.
Look, we're dealing with ultra potent compounds with short history of use in humans and there are acute and chronic dangers involved that quite frankly I find concerning and have made me decide not to use them. Do you really want to increase the chance that things go wrong by boosting your peak plasma levels?
Also I think a long term side-effect subthread is warranted and I will be moving syle's post + response post(s) there. Whether or not you find the issues people report to be of considerable gravitas, we need to pool that data.