This over-the-top item has come to me from several sources recently:
Just packed with sexual suggestion, playing the phallicity of celery stalks for all it’s worth.
The image is clearly scanned in, but I don’t know from where. The Devil Chef figure might be borrowed from the cartoon character, in a one-shot comic book of 1994 by Jack Pollock in which “the diminutive demon of disagreeable delicacies”, the DicTater-Tot, terrorizes the patrons of Chez Monieux (shame on you!):
Back in Celery Land, we have “Nature’s Toothbrush For Your Colon”! “Ooh LaLa!”, it’s “Ribbed for Xtra Pleasure” (just like a ribbed condom). And the visual shows a distinctly mouth-like rectum being scrubbed for health. (Someone wielding a penis rather than a toothbrush might reasonably worry about the rectum dentatum.)
In answer to the question, “What else can you masturbate with instead of a dildo?”, WikiAnswers recommends a long list of things, including (under Household Objects) the handle of a toothbrush (note: not the brush!) and (under Fruits/Vegetables) cucumber, carrot, celery, and squash.
But this is not the end of celery’s sexual utility. From a site on botanicals:
Celery has been considered a very suitable food for the proper maintenance of sexual relations. It is considered a good aphrodisiac, increasing sexual desire and facilitating the erection of the penis. (link)
Other sites suggest that the (claimed) sexual benefits of celery aren’t merely symbolic reflections of the stalks’ phallicity, but also have some biochemical reality, in phytochemicals; I’ve seen no actual studies.
Finally, a potential role for celery in fellatio:
To maximize oral sex, it is worth paying attention to what food you eat. Foods such as kiwi, celery, and pineapple can make genital secretion sweet. Dairy products, meat, and alcohol are generally thought to worsen the taste. (link)
Truly a wonder of nature (and rich in fiber and very low in calories).