Tongue Twisters

According to researchers (I don't know who) this is apparently the hardest tongue twister ever:

 

Pad boy poured card pulled cod. (What does that mean?)

 

and this is another good one:

 

Suzie sits in a shoeshine shop.

where she sits, she shines.

where she shines, she sits. (YIKES)

 

which is reminiscent of my personal downfall about a hundred years ago:

 

i split a sheet. A sheet I split. 

And on this split of sheet I sit.