I dose all my 25x-NBOMe tabs intranasally. I don't even bother to extract them off the tab, however. Dissolving in EtOH/Water and insufflating the solution will inevitably cause loss of some of the drug, depending on how long you leave them in the solvent, whether you tear them up, and so on. A much more convenient way to insufflate the NBOMe is simply place the tabs into your nose and leave them there for 30-60 minutes. Having a fair bit of experience dosing NBOMes this way, I have perfected a method that maximizes absorption while minimizing unpleasant side effects(I find the comeup to be very quick and intense, so I stagger the dose... this is personal preference):
-Cut your desired dose up evenly; If you have 1 tab, cut into two half tabs, If you have 1.5 tabs, cut into two half and two quarter tabs, etc.
-Wet your nasal canals. I use saline spray, you can also use a neti pot. This is to prevent bleeding and damage of the tissue from the tabs; I assume it is due to the fact that my tabs are HCl. In my experience insufflating drugs that contain HCl will almost always cause breakdown of sensitive tissue.
-Lightly spritz the tabs with water or liquid to ensure the tab will stay put in your nose. You can use a spray bottle, or simply drip water from the faucet carefully onto the tabs. Do not use too much water! You will lose a considerable amount of NBOMe doing this.
-Place an equal amount of NBOMe tabs in each nostril. Make sure the entire surface area of the tab is touching the skin of your nose. Hold for 15-30 minutes. Once that is completed, flip the tabs over, again making sure the entire surface area is covered and holding for an equal amount of time. Personally, I find the comeup too fast taking my dose all at once. I stagger the dose, placing half my dose and flipping them after 15 minutes then taking them out after 30. Then after an hour or two, I repeat the same process with the second portion of my dose. Although more experienced psychonauts may be able to handle the come up better than me.
So there you go. I find this method much more efficient than dissolving in a solvent and insufflating liquid. Be careful, the comeup is faster and the bioavailability is higher, so the drug will kick in faster and harder but wear off faster than sublingual dosing. I have tried dissolving it in a solvent and insufflating but even with an equal dose every trip I found the dosage to be wildly unpredictable and hit or miss.