How about some 1-word searches?
non-nude and clothed both return nothing but porn.
At least burka returns some non-porn images.
Google Image searching just now, “stars” brings me a nekkid female, squatting, with a wide-open beaver.
Trying to put together a slide show for church, here, people, quit showin’ me all this pron…
Nun.
The second image is a nun with her tits showing. It only gets nastier from there.
pwned
I thought Big Mac would bring up something. But, I didn’t find the safe search to turn off. There is a young girl on a Bike that looks interesting. She goes by the tag Big Mac I guess so she made the first page.
“Shaved” brings up nothing but porn, but I guess that’s too easy.
A corollary challenge would be to find dirty-sounding phrases that don’t turn up any porn: “Tool Chest”, “Dick Trickle”, “Little Big Muff”, “Spotted Dick”, etc.
Huh, for me “rooster donkey dog” is mostly pictures related to the story of the Bremen Town Musicians, no porn; “cock ass bitch” is almost exclusively pron. Are you sure you have safe search off.
I found one (kinda tame) with “mostly harmless”.
I just now entered the word “bubble” in Google images, no intentions of looking for porn. Still, the first page returned three images of a pornographic nature (I’m at home and not at work, fortunately).
Among the same lines, “apple” should probably get you porn too. I’m too lazy to look, though. 
“Apple” gets a bunch of computer stuff.
“Hello” gets some porny stuff. Same for “friend.” “Nice” is total porn.
Burger King turns up a chick in a bikini on page 1, and then nothing for at least 8 pages.
Unless you count food porn, that is.
tarzan jane comes up with an interesting combination of movies, Disney and porn.
Whoever would have dreamed that there are so many attractive Hispanic women with the name Griselda?
Oddly, “tab a into slot b” does NOT bring up any pornographic photographs. There was one hastily=scribbled cartoon, though.
‘Kittens sunshine’ yielded no porn at all in 20 pages (when I got tired of looking). There was a woman in a bikini on the very first hit; a message board avatar of (clothed) cleavage on page 8; and a photo of Paris Hilton (fully clothed) with a Persian kitten on page 14.
Since this is basically a game thread, I’ll move it to The Game Room for you.
Cajun Man
for the SDMB
Huhuhuhuhuh. You said “Google”.
One Two Cup
What do I lose? (besides my lunch)
“clock mouse golf”
…gives you a picture of a pair of women with their tits out and decorated like Mickey Mouse on page 9.
It took 10 pages to get to something NSFW with “hello world”.