Anything even remotely phallic shaped and sized has probably been used like that by someone. Depends on how horny you are, both in the moment, and as a person in general. I’m a guy, but during puberty, when I was exploring masturbation and bottoming, lemme tell you, nothing was safe from getting fucked or fucking me.
I wouldn’t be overly concerned about your produce, though. Most folks would toss it afterwards. If you notice your cucumbers or bananas going missing, then it might be cause for concern. But honestly, if your kids are at that age, and you’re genuinely concerned they’re doing something that might cause harm, the bigger concern is a lack of information about safe sex. A no questions asked Amazon gift card is one idea, but I’d recommend finding a good book or website you trust with sex Ed info, including safe solo sex practices, and an agreement that packages that come in their name aren’t to be opened by anyone else. In my experience, parents who trust their kids and don’t snoop or invade their privacy have way less to worry about from their kids than the parents who toss their rooms. My friends with the strictest parents had great hiding spots, I never even tried to find any. Didn’t need to hide anything, and as embarrassing as it would have been had I gotten a cucumber stuck up there or something, I would have been able to tell my mom and get a ride to the ER. If your kids seriously don’t trust you not to freak out, they could end up literally dying because the embarrassment would be worse than not dealing with a medical issue.