Hi. Greetings. Seborrhoea capitis/ seborrhoiec dermatitis or dandruff is a chronic problem. Please note. Avoid using oils on scalp. This acts as food for  fungus causing dandruff. You can apply it only at the hair part and not the scalp for short durations if you particularly wish to. Certain oils must be avoided   Secondly wash hair with antifungal / low strength corticosteroid based shampoos at least twice a week. Use maintenance shampoos regularly. You may need a course of oral antifungals if your condition is severe. See a dermatologist near you. Hope this helps. Further queries may be sent on Warm regards Dr Govind S Mittal.