I agree that clotting needs to happen to seal off any wound, and Dengue infected blood is not capable of doing so.
But the bleeding itself happens when the Dengue virus tore down tissues and blood vessels, which allow the leaking of the blood causing hemorrhage in the brain and parts of the circulatory system, and water leakage causing dehydration.
This means that the Dengue virus is able to replicate so fast that the autoimmune system is effectively defeated that no amount of conventional drugs are able to neutralize.
Indeed, it is impossible for any toxic drug to do so since its own toxicity poisons the neuropeptides that the immune system is relying on. This same toxicity also adds to the burden that the liver and kidneys need to detoxify the body from.
The only sane approach is to use a non-toxic medium like the electric current to directly neutralize the Dengue virus, any virus in fact, through the arterial blood. You can do this viral electrification non-invasively through a device called Virutron. Just google for it.