Dust on the lens or the sensor can be removed without any problems with the bellows + dust brush. For smeared surfaces, the cleaning liquid is used. Cleaning should necessarily happen in this order to be rubbed with the liquid and the subsequent polishing scratches.
The supplied paper fluff too strong for me, but I use a microfiber cloth (for displays, such as included with the iPhone).
A little hint yet at the end, I always put the bellows with cleaning brushes in a plastic bag for storage. Otherwise sucks the brush over time dust, which you then blows on the sensor during cleaning.
Conclusion: For the money, a top product, the supplied paper could be better and more.