Is it valid to perform ghusl without shaving the pubic hair and armpit hair for more than 40 days, and is it sufficient to sprinkle water on thick pubic and armpit hair, and how should it be shaved?

Ghusl is valid without shaving the pubic hair and armpit hair, provided that water reaches the skin and the roots of the hair. Merely sprinkling water is not sufficient, because it is obligatory to make water reach the skin and the hair roots in an obligatory ghusl, due to the Prophet's (peace be upon him) saying: "Indeed, there is janabah under every hair, so wash the hair and cleanse the skin." It is not necessary to shave them if they do not prevent water from reaching [the skin], but it is disliked to leave them for more than forty days, due to Anas's (may Allah be pleased with him) saying: "We were given a time limit... not to leave [them] for more than forty nights." The best for pubic hair is shaving, and for armpit hair is plucking, and it is permissible to remove them by any means that does not cause harm. What is required is to shave all the hair.