Is inserting a cotton swab or tissue into the vagina to ascertain ritual purity after menstruation considered valid, especially when there are internal bloody discharges that do not appear externally?

The outer part of a woman's private organ must be washed during istinja (definition)' (ablution after defecation or urination). This is the part that becomes visible when she squats to relieve herself. Menstruation is only confirmed when blood reaches this outer part, and the fast is not broken if something enters it. As for the inner part of the private organ, it is not obligatory to wash it during istinja', nor is menstruation confirmed by the presence of blood within it. A woman recognizes purity by one of two signs: dryness (jufuf) or a white discharge (al-qassah al-bayda'). The criterion for dryness is that a woman inserts a piece of cotton, and it emerges clean, with no trace of blood, yellowish discharge, or brownish discharge. The cotton must be inserted only into the outer part of the private organ. If the cotton emerges clean after being inserted into the outer part of the private organ, then she has become pure and must perform ghusl (definition) (ritual bath). If it emerges stained, she is still menstruating, and what is in the inner part of the private organ is not considered.