In this method, a person should first make a niyyat for Ghusl. Thereafter one should first wash one's head and neck, and thereafter the remaining parts of one's body. It is better that one washes the right part of the body first and then the left part. And if a person, while standing under the water, jerks each of these parts on one's body with an intention of performing Tartibi Ghusl, it will not be sufficient and the precaution is that one should not content oneself with it. And if a person washes the body before washing the head, either intentionally, or on account of forgetfulness or because of not knowing the rule, Ghusl is void.
Musturbates is haram watching is also Haram it is a gunah e Kabira
But it will not causes to exit Islam