Breathed by who, Law Student? Don't you find it odd that there is no documented case of in vivo elective consent for liquid breathing to be found?
Yes, trials have occurred, but they have taken place with either patients who are gravely ill or in premature babies. Don't you consider that odd?
I was in the USA when the FDA stopped one such trial because of ethical issues involved, a matter that seems to have escaped the compilers of Wikipedia. Until we overcome such issues, the procedure will remain highly experimental.
Regretfully, "The Abyss" has much to answer for.