You can use the spray wiper both with and without detergent.
Please note that the wiper can be stored with water in a tank, if this contains no detergent.
If you want to use a detergent, 1-2 drops is enough for cleaning. Please ensure that you rinse the tank with hot water after use. Any standard detergent can be used, however you should make sure that this is not an aggressive detergent.