Hello,
Thank you for asking your query.
As a rule of thumb, its not wise to put anything into the ear. With out medical guidance it won't help in any ear condition. But you need not worry now. The crackling noice could be due to Eustachian tube dysfunction which is a very common ear disorder. This tube connects ear to nostril and when it gets blocked the crackling occurs.
Now the deafness should be temporary due to the oil stuck in you ear canal. I recommend you to lie down on that side of the body while sleeping. This will help in draining the oil out. Also keep the ear dry while showering. Steam inhalation twice daily with open mouth can also help in this and the crackling.
If still the deafness is persisting for more than 1-2 days with these measures you may need to see your Doctor.
Hope this helps.