It can be done with sunflower oil but if you want to get good health benefits you should do it with coconut,  sesame seeds oil,  olive oil or mustard oil. It depends what benefits you want out of it.  For different symptoms and doshas different oil works better. Morning time is best for oil pulling because all toxins collected in oral cavity after long sleep.

Oil pulling is a procedure known kaval in Ayurveda. It cna be done with oil, decoction, ghee or honey also. It depends on dosha predominance. It can be done anytime preferably in morning. On daily basis tila oil is best.

Brother you can do oil pulling at any time if you are  extra busy with your work but if you want best result you must do it at morning time.

Feel free to to consult with the

You can do oil pulling with safflower oil. Morning time is ideal option , even twice in a day ( morning and night ) is best . You have to change oils weekly or couple of days later sesame oil / coconut oil /olive oil /sunflower / safflower oil for gargling

U can perform with mustard oil or coconut oil at night