Praise be to Allah.All Grace is due to Allah;
It mandatory for a Muslim woman to perform Ghusl after her menstrual cycle so she can perform Salah. It is not permissible for her to have intercourse with her husband until she performs Ghusl, as Allah Almighty says(Interpretation of the meaning):
".. and when they have purified themselves( from menses have taken a bath) approach them (i.e. for Intercourse) as Allah has ordained for you(i.e. in any manner so long as it is in the vagina)"
Purification does not mean merely that the blood stops, but also the act of Ghusl afterwards. It is performed by washing the whole body, and it Sunnah to wipe the area from which the blood effuses with a perfumed(Musk) cloth. As indicated By the Hadeeth, the prophet ( peace be upon him ) says:
"Take a piece of cloth or cotton that is perfumed with Musk and purify yourself with it".
May Allah guide us to the right path.