Some permutations of phrases already mentioned:
(he looked like) Death warmed over
get your shorts in a wad
Ass over teacup

And some fresh ones:
slick as greased owl shit
don't that just rot your socks?
Ain't worth sic'em (not worth setting your dog on him)
something you choke on "goes down your Sunday throat"
the thing what lives down the drain and makes the wierd noises was called "Gobbledy-gook" according to my grandmother.
barking spiders (flatulence)
trolleywagger (loose thread on your garment; from the electric connection wire that either connected or grounded the overhead wire trolleys where I grew up-- Detroit MI)
baggies and squeezers -- two kinds of men's underwear.
utrou (pronounced you-trahw) men's underwear. army? an abbreviation for under-trousers.
thundermug -- chamberpot

And from the movie "Nurse Betty":
She's as nutty as my shit after a pound of Almond Roca.

I can understand about a bankrupt enterprise going "belly up", but where do you suppose "gunnysack" comes from?
blessings,
Barbara