Why shaving razors dull

[KnifeGrinders]

By what I remember from school, oil cannot displace water, the oil will be over the water droplets on the razor.

Rinsing in distilled water is sure a solution.
Demineralized water in Australia costs about $1 per 1L. 1 cartridge razor costs about the same. But we can rinse our razor in the same cup of demineralized water quite a number of times, before replacing the water.
And we do not even need to blow that water out of the cartridge razor.

Thanks for the idea, Grepper!