In most purchase order financing structures the money never reaches your bank account. The funder pays your supplier directly, or issues a letter of credit the supplier draws against on shipment. You are not receiving working capital to deploy as you see fit; you are having a specific production cost paid on your behalf against a specific order.
That single fact explains nearly everything else about the product. It is why funders care more about your supplier and your customer than about your balance sheet. It is why the money cannot be used for payroll, rent, or the tax bill that is also due that month. And it is why PO financing almost never solves a general cash shortage — it solves the narrow problem of an order you cannot afford to fulfill.
If what you actually need is flexible cash across the whole business, a revolving line of credit or an asset-based facility is the honest answer, and a good advisor will tell you so before running a PO deal.