If you have never cleaned your sensor before it is very likely that you do have some oil or grease on it that has been thrown off by the shutter mechanism. So a Rocket blower won't work, and you don't want to try a brush, such as an Arctic Butterfly, because that will spread the grease and it will contaminate the brush. The oil problem on the sensor does go away after a few cleans, and then you can regularly use blowers or brushes (with a wet clean every few months if you are lucky).
So you need a wet cleaning kit, there is no way around that. Visible Dust make a good product, but there are others available. Do not try one of the 'sticky pad' systems as they cannot remove oil. The temptation for beginners is to try whatever seems easiest (like blowers etc) but wet cleaning is easy if you follow the instructions, it just doesn't sound easy.
Steve