This kind of sealant performs very well, but it doesn't last forever. It's not the first time that someone decides to make a bit of do it yourself applying silicone because at a first glance, it seems easy!
The problem is that this sealant sticks to every surface, even in those that you don't want at all. And, for sure some silicone needs to be removed and conditioned for looking even, a process usually done using a finger.
There's a method, however, to not create a mess with silicone using toilet or kitchen paper, preferably the first one. The finger passes in short distances of about 8 centimeters / 3 inches, and the user pastes the excess sealant in the paper creating after it a fold to hide the silicone. This way, with a strip of perhaps a meter and creating a few folds, the user can get rid of the sticky material without problems.
Another convenient trick once the finger is passed would be spraying on the surface with soapy water or similar to create a wet layer. That prevents the silicone from sticking to the surface, and then, with the help of a little plastic card, it's easy to remove the excess silicone from the surface without using other techniques like tape or more paper.