What is the ruling on using starch to beautify some sensitive areas?

The jurists differed on the ruling of using food for personal hygiene, holding two opinions: The first is permissibility and lawfulness. They argued that personal hygiene and beautification are sanctioned matters, and that this constitutes utilizing, not wasting, food. The second is reprehensibility, especially concerning staple foods, because it may lead to their contamination with impurities, and it is a form of extravagance and squandering, which Islam has forbidden. It is preferable not to use food for personal hygiene due to the availability of many alternatives, unless there is an extreme necessity for it.