The liquid is dense, but has a low surface tension, so will flow into every area without the need for pressure. This technique is already saving babies . Again, liqwuid ventilation can be used. The perfluorocarbon will gently inflate the lungs, pushing the distended organs into the lower cavity. Filling the lungs with a liquid can be used to clean out any debris.
Foreigh matter tends to float on the dense liquid and is therefore readily removed.
Perfluorocarbon liquid has been used to remove aspirated charcoal and also aspirated vomit from human patients. Whether these are realistic concepts remains to be seen. See the work by Carl Davis at the Royal Hospital for Sick Children, Glasgow. Article in Pulmonary Perspectives TH Shaffer et al, Art. Cells, Blood Subs., and Immob.