I didn't want to just limit it to horrible pick-up lines, like:
"I'm adding you to my to-do list!"

But also all-around bad ideas for courting, like:
Exploit Stockholm syndrome!

Have fun.

Liberal application of enadoline or salvinorin A.

Paying off parents and funding-hungry behavioral biologists to condition someone from early childhood to respond favorably to you or someone of your choice.

3-quinuclidinyl benzilate

Münchausen syndrome by proxy

Quoting anything Absentwizard just said

Asking them out... to see the local markets. Not as appealing as it appeared at the time.

To extend on Shirocco.

Asking them out... to see the local stock market.
Asking them out... to see the global commodity futures markets.
Asking them out... to see the nearest mint.

Not so bad idea:
Asking them out... to see the local wineries and tastings.

Let's try to stick to bad ideas so nobody gets any bright ideas and tries them and comes back to sue us. It could happen!

Bad pick-up lines:
"When the zombie apocalypse comes, the survivors are going to have to repopulate the earth! Wanna go back to my place and practice?"

"You must be tired. You've been running through my mind all night... SCREAMING!"

One of my favorites in-context - at a gym: "Do you work out?"

Anything from Alien Loves Predator.

Bad courtship ideas:
Crash into a pretty woman driver you see on the highway so you can exchange phone numbers.

Pretend to be gay so women will feel comfortable undressing around you.

Put women at ease by insisting that everything you do, no matter how innocuous, is not sexual. e.g., "I just want you to know, my buying these five cucumbers, two melons, and bunch of bananas... That's not a sexual thing."

Kill every attractive male on the planet so that eventually you'll rank as most desirable.

Bad pick-up lines:
"IITYWIMWYBMAD"

- "If I tell you what it means, will you buy me a drink?"

LOL...yeah...that's bad. I would never undress in front of a guy thinking it was ok because he was gay. That's hollywood b.s. We don't do that.
I could write a book on bad pick up lines that I have had used on me or my g/fs. (And a few I actually thought were cute)

We have the time.

LOL....now now Viletta Vadim...this is a thread about bad courtship ideas...not bad pick up lines.

Oh no, bad pick up lines totally count too! I just didn't want to exclude other ideas. Go ahead and tell us your list.

Hah, and if you were wondering up until now why I don't get the chicks... now you know.
And that's half the battle.
The other half is violence.