Some people are hesitant to do so because they fear that water and electricity should be treated separately.
Spraying water outside your air conditioner is OK, especially if you need to clean the outside unit.
There is no downside to doing so. On the contrary, spraying water on your unit's condenser can improve efficiency.
This is because the condenser needs a regular shower to function correctly. If your air conditioning unit becomes problematic after being sprayed with water, you should get it checked by a skilled HVAC specialist.