The wood that expands past the edge of the "mouthpiece" has nothing to do with the ability or inability to bend notes.

Furthermore, there is no reason to use Marine Bands "only". Contemporary blues players use a variety of brands.

Furthermore, the OP said nothing about playing blues - but he did express interest in "Old Time Harmonica" and "Old Time Music".

Oh yes - do NOT soak your harp in beer. Most authorities do not recommend soaking it in anything nowadays. However, there are those who feel that soaking wood-combed harmonicas in water helps temporarily with achieving a fuller sound, at the price of briefer life for the instrument.