Here’s my feelings on the thing about that:
Many moons ago in the early days of harmonica, there was very little instructional materials available on it.
So those who did put out books and tapes on how to play were put out by those on how “they” played! It was only by consensus that many of them talked about using a ‘pucker-style lip’ block to sound the notes. Yet there were a few others who did use a ‘tongue-style’ block - either side of the tongue or U-shaped tongue - to sound the notes. Neither side though actually agreed.
However, along comes the Internet, and with the big bang of the vast & mighty Harmonica Universe at one’s fingertips – With people who demonstrated that there is a third way to play notes, we now have factual documented proof and total agreement. Meaning: Do whatever works for you at the time you’re doing it!
I use various methods because over TIME they just came to me as I worked and learned along with them.
And we have had many discussions on the subject as well. Here’s just one thread on it:
Bottom line is: Don’t get your shorts, or better yet your lips all bunged up over-thinking am I doing this right or not! Especially when it comes to just playing and having fun!
Hope this helps!
Keep On Harpin’!