Sublingual doesn't work for me. I did use a nasal gel for a while about 10 years ago with good results. That product (called EnerB) is now off the market - at least I haven't seen it. I'm not sure about the physiological reason, but I know that injections are sure fire for me.
In the days of yore, the old blues players would stay up all night drinkin' and playin' and take a B12 shot the next day for a "pick me up" - I'd like to have the shots at times, because I don't really feel the cyanocobalamin.