Sick of the same old bullshit expressions? Shut up, of course you are. To help with this problem of yours I invented a new expression you can use. It's not "weekend at Dracula's" but that one's pretty good too.
The Expression: I wouldn't even tell Dracula.
Usage: Use it when you are swearing that you'll never tell a secret. It's like putting something in the vault.
Person 1: Oh man. Now that you know my secret, please don't tell my wife that when I'm home alone I like to put on sunglasses and a fake moustache and role-play as Bernie's corpse from the film Weekend at Bernie's. And only the first movie. I don't do that bouncing around zombie Bernie bullshit.
Person 2: Don't worry dawg. I wouldn't even tell that shit to Dracula! And you know he takes that shit to the grave!