In this PowerPoint themed lecture, Sheikh Bilal Homaysi begins with the Chapter of the Integrals & Recommendations of the Ghusl. The integrals are that which the obligatory Ghusl would be invalid if left out while the recommendations are the matters which if it is left out, the obligatory ghusl is still valid, however, there would be less rewards.
Sheikh Bilal Homaysi explains each point in detail.
YouTube - https://youtu.be/Esy4Ko3xvT0