You can check Sir Waqar hassan on YouTube. He will be starting new batch soon. His fees is 21k for 4 months in which he teaches 10 essays. As far as checking is concerned he just checks 2-3 essays and for rest you will have to pay 600 per essay. I didn't join him because of lack of time.

Thing is every teacher has his/ her own method of dealing with essay. No method is wrong since students from every corner pass essay. However, there is no teacher who can even claim that 10% of his/ her students passed.

It all comes down toy our own hardwork and luck.