Learning a language is like committing murder.
Although all forms of murder basically amount to suffocation, immolation, stabbing (direct organ and tissue damage) or “overwhelming the immune response”, there are an infinite number of variations within that.
So to say “only method X works!”, “method X is the correct way” is like saying “human beings can only be killed using a Glock 17” — which simply isn’t the case.
What if you don’t have a Glock?
Shouldn’t you use that Magnum? Or that cheesewire? Or that bottle of arsenic?
1. Do what you like.
2. Use what you have.