If you'd like a taste of wretched writing, check out SJSU's Buler-Lytton Fiction Contest, which challenges aspiring writers to compose an opening sentence to the worst of all possible novels. The 2005 winner, just announced, opens by comparing a woman's "ample bosom" to an old auto carburetor. What more do you need to know!
Personally, I think a little wretched excess can be a good thing. In my writing classes at SJSU, I sometimes read some bad similes and metaphors to my students to get them to lighten up and feel more confident about crafting their own ("hey, my simile can't be any worse than that..."). Bad examples -- combined with some good ones too, of course -- can help students "get" the basic concept. Besides, reading the bad ones out loud makes me laugh...and that's always a good thing.
A good source of really bad similes is Oakland high school science teacher Anthony Cody's collection of the "worst analogies ever written in a high school essay." Enjoy!