I have long hair which I can't get cut due to barbers being closed due to COVID-19 Lockdown Restrictions. This makes it quite difficult for me to make ghusl since you have to make sure the water reaches the roots of your hair. This can make ghusl time-consuming and often means I don't have time to do ghusl As quick as I'd like. I do Ghusl in the shower (I don't have a bath) so my question is if there is any specific instruction for how hair is washed during ghusl? and how to do it quickly and efficiently.
Also for reference, my hair is long enough at the front to just cover my eyes and about halfway down the neck at the back so it's not super long.