Your Merkur razor is a quality piece of engineering and should be treated as such. The following is from Merkur regarding the maintenance of their safety razors. Please note that failure to follow these maintenance guidelines could invalidate your warranty.
Maintenance of Merkur Safety Razors
In order to prolong the live of your safety razor it is necessary to clean the moving parts of your razor after each shave, for example with a soft nail brush or tooth brush. Only if the soap residue is removed thoroughly, the mechanics of your razor will work satisfyingly in the long run. We suggest to completely break down your razor for a thorough cleaning with each new blade that you install in the razor.
"IN CONTACT WITH HARD, CALCIFEROUS WATER all parts of the razor need to be decalcified regularly, depending on the concentration of lime in your water. The parts should be put into a diluted and lukewarm decalcifying solution for a maximum of 15 to 30 minutes and should be moved in the solution every few minutes. It is also recommended to move the mechanical parts a few times, so the solution can get into every crevice. A more extended contact with the decalcifying solution will destroy the surface and corrode the metal of your razor,"
DOVO/MERKUR Stahlwaren, Solingen-Germany