The best way to grow your eyelashes in 3 days is by using castor oil.
Castor oil when applied to your eyelashes helps stimulate circulation and helps promote the growth of the eyelashes and although the eyelashes won't grow fully in 3 days you should see some eyelash growth after 3 days of apply castor oil to the eyelashes.
For best results you should apply castor oil to your eyelashes everyday twice per day for the 3 days or until you see your eyelashes grown to the length you want them to grow.
It can take a week or even month or two to see your eyelashes grow fully but using castor oil does help promote the growth.
Coconut oil and Vaseline can also help your eyelashes stay moisturized and help them grow too.
Both Coconut Oil and Vaseline are great for eyelashes but when it comes to which is better than the other the Coconut Oil is much better for eyelashes.
Coconut oil is much more moisturizing for your eyelashes but you get even better results when using both coconut oil and Vaseline for your eyelashes.
I would use coconut oil on the eyelashes first and then apply some Vaseline afterwards as the Vaseline can help seal in moisture.
Castor oil is also great for eyelash growth as the castor oil helps stimulate circulation as well as promote the eyelash growth.
I use coconut oil along with Vaseline and sometimes Castor oil on my eyelashes and it helps my eyelashes grow thicker and faster.
Trimming your eyelashes can also make your eyelashes grow back thicker and faster as well.