Is it necessary to remove perfume, ointment, or oil with soap before ghusl, or is water sufficient? Is it necessary to remove oils or creams from the hair with shampoo, or is water sufficient? Is the presence of a frozen white substance on the nipples or dirt under the nails considered a barrier that prevents the validity of ghusl? Is it necessary to clean the teeth during ghusl? Is one ghusl sufficient for more than one event (such as menstruation, janabah, احتلام (wet dream), and Friday)? Is it permissible to use shampoo and soap during ghusl due to waswas? Is it necessary to say "Bismillah" before or after istinja in ghusl?

There is no obligation to remove oil from the body or hair for ghusl (ritual bath), unless it has solidified and formed a barrier preventing water from reaching the skin. It is recommended to trim the nails and clean beneath them, but slight dirt does not invalidate wudu (ablution) or ghusl.

As for a barrier that prevents water from reaching the skin, it must be removed, unless its removal is difficult or would cause harm. Brushing teeth before ghusl is recommended but not obligatory.

It is permissible to combine multiple ghusls with a single intention, and saying Bismillah (in the name of Allah) when cleaning oneself after relieving nature is not from the Sunnah, but it is recommended before ghusl, while avoiding mentioning the name of Allah in the bathroom.