You should continue to wash your hair according to any routine that works best for your scalp, and does not cause irritation or dryness. Over-washing the hair can be counterproductive, and should be avoided.
With Topical Finasteride with Minoxidil Spray, the recommendation is to wait for a minimum of 3-4 hours after applying before washing the hair, in order to allow sufficient time for the medication to be fully absorbed into the hair follicles.
For this reason, applying the treatment shortly before going to sleep is often recommended as a convenient and suitable option for the application of this treatment.