So I was kind of competing with my sister and forcing my dad to do some toungue twisters. My dad seemed to only know one vietnamese one with alla these B's so I told my sister to go look up some. 

This is the one my dad knew: 

Bà ba béo bán bánh bèo bên bờ biển.

Translation: The chubby woman Ba sells rice cake on the sea shore.

But the best one I found? er... we found? 

Mặt mập mọc một mụt mụn bọc
Hai mụt mụn bọc mọc mặt mập
Mặt mập mọc ba mụt mụn bọc
Bốn mụt mụn bọc mọc mặt mập

Are you guys ready for the translation?? ok ok ok

Translation:  A big face has a pimple. Two pimples grow on a face. A big face has three pimples. Four pimples grow on a face.

lol i can't... i'm dying xDDDD my dad had such a hard time saying this one LOLOLOOLOLOLOLOLOLOL 

i got them from here: http://www.uebersetzung.at/twister/vi.htm

those were the main ones though... my dad said the other ones too easily =.=