Actualy, blood choke is more effective,making it potentialy more dangerous.If held for around 40 secs. causes death or brain damage.Also certain segments of the population have lost elasticity in wall of blood vessels due to pathology, age, etc.-once blood vessel is closed,it does not naturaly reopen.
But in general you are correct Jkogas.

Airway chokes are dangerous because of high potential for damage to trachea.Applying pressure to trachea can irritate it,causing it to swell shut.Can cause rips or tear,causing blood flow into lungs-filling lungs with fluid.