Is it sufficient to insert a cotton swab 1 cm to test for dryness after menstruation? And is the cessation of blood, dark discharge, and yellowish discharge for 16 hours an indication of purity (Tuhr), or are clear, uncolored discharges the sign of purity?

"Dryness" means that a woman inserts a piece of cotton into her vagina, and it comes out white, without blood, yellowness, or a brownish discharge. Normal wetness does not matter. As soon as a woman sees this "dryness," she must perform ghusl (ritual bath) immediately. If blood returns after "dryness," she is considered menstruating again, as long as it occurs within a period suitable for menstruation. If she sees yellowness or a brownish discharge after purification, she should not pay attention to it unless it occurs during her usual period. It is sufficient to insert the cotton only into the external part of the vagina.