"This above all: to thine own self be true":
- use Dr. Lozanov's insights, they are revolutionary and empowering and the world needs them, and Dr. Gateva inspired very many teachers and learners: but it's not Lozanov standing in front of your students, and it's not me - it's you, and they're your students and it's you who knows them, if they're not self-motivated and well-behaved middle-class adults who feel comfortable with the sound an opera-singer makes, they may not react just the way the book says. Only you can judge what works for you and your situation.
"And it must follow, as the night the day,
Thou canst not then be false to any man.
Farewell"