If you blow a cockroach into the sink and wash it down the drain, it is highly likely that the cockroach will die. Cockroaches are not adapted to survive in water for extended periods, and they can drown or suffer from other adverse effects when exposed to water for too long.
Cockroaches have a spiracle system that enables them to breathe air, but it is not designed for underwater respiration. When submerged, they may struggle to access oxygen and eventually suffocate. Additionally, the force of the water flowing down the drain can be strong enough to injure or kill the cockroach.
It's important to note that cockroaches are resilient creatures, and some species have developed adaptations to survive in various environments, including wet conditions. However, even these species have limits to their ability to survive underwater, and they are not well-equipped for navigating drainage systems.
While it is difficult to definitively state what happens to a cockroach in every scenario, it's safe to assume that the majority of them would not survive being washed down the drain.