Muslim scholars have stipulated that in order to deem washing of an organ in wudu or ghusl as valid, water must reach the skin. This is a generally accepted view of all of the Schools of Jurisprudence. If water does not reach the skin, this means an essential pillar of wudu‘ or ghusl which is washing such part is missing. Washing means passing water over the organ and it must touch it.

For more clarity on this and specifically on substances that are capable of blocking the water from reaching the skin during ablution or ghusl, Zienab Mostafa, a prominent Muslim Scholar and Da`iyah, stated that if a woman is sure that a particular ingredient used for beautification creates a barrier that blocks the water from reaching the skin, then she is must remove it before the wudu’ and ghusl.

She also advised that It is better and safer for Muslim women to use the normal henna that does not prevent the water from reaching the skin.