This is awkward...
Okay, first of all, at 13, you really shouldn't be doing that for..."recreational purposes", you can find something else to do. Try finding an online video game, playing a board game, or talking to friends.
If you must, there are many alternatives to this subject. A toothbrush. A mechanical toothbrush can sometimes vibrate in a pleasing manner. A handle to something. A broom handle is too long, and can rupture internal organs. Something like a hand broom, a lint roller, or something thats cylindrical and isn't blunt, it should have a rounded tip, like what it is pretending to be.
And whatever you try to use, make sure that it is clean, and covered. If it isn't clean, you can get a horrible infection, and if it's not covered, you can get cuts, splinters, burns, and anything else you don't want down there.