Blow your nose. Before using the nasal spray, you need to clear your nasal passages. Otherwise, the medication might get caught in the front of the nostril, where it will be less effective. Blow your nose until you have completely cleared your nostrils. 1  Do not blow your nose after using the spray.
The basic difference is the pin of the transistor that is grounded. The common collector has the collector pin grounded, common emitter has the emitter pin grounded and common base, as you guessed it, has the base pin grounded. The following article explains the differencnes perfectly.
Also not that the collector voltage is higher than the base voltage. The main differences between emitter and collector are doping concentration and size. The emitter is heavily doped, while the collector is lightly doped. You could try to swap them, but you'll get a very low \$H_{FE}\$, probably even less than 1.