First of all, way to go, and I hope you are able to introduce understanding into the hearts of many.
Where is it written “Woman is a sack of excrement with a bleeding hole”?
Who wrote it, and how do the religious explain preserving this sentence over the course of generations?
The sages of the Talmud customarily spoke with mockery and belittlement about women, even those women who were prophets — Devorah and Chuldah. They degraded the women and claimed that the women deserve no respect and that their very names are disgusting; Devorah (bee) is the name of an insect and Chuldah (rat) is that of a rodent. Thus, too, they spoke of Avigail the prophet; when she was still married, the sages claimed, she hinted to King David that he would marry her. They interpreted her words to David, quoted in the Scriptures, “When the Lord shall have dealt well with my lord, then remember your handmaid,” — Rav Nachman said, “There is a folk saying: while women talk, they spin their own wool” [while a woman talks she watches out for herself; while Avigail talked to David to save her husband, she also made sure to hint to him that he should marry her after her husband dies] (Megillah 14b).
That is why they also described women in a disgraceful manner: “Woman is a sack of excrement and her mouth is full of blood, but all run after her” (Shabbat 152a).