My experience
I've found that almost anything that was meant to be held with a human hand can be used as a butt plug, especially if you have a soldering iron, heat knife, or, if you want to take a long time with it but have no other option, a lighter and a metal nail. I have a lovely dildo made of the plastic handle of a plastic pingpong paddle (the whole thing is plastic and the center where the ball is supposed to bounce off of was just a thin sheet of plastic which I cut out with a knife) it starts out as a ball about one inch in diameter and flattens out to the handle which is about one inch long and a half inch thick (like an ovalish cylinder) and continues like that for like 4 inches until it widens out to the circle that made the paddle. I'll soon be modifying it so as to make it an overnight butt fuck
but that is easy enough to do when you have 3 different types of soldering irons.
DO NOT try to turn anything into a vibrator without extensive research and testing - you can put your fingers on your car's 12 volt battery and feel nothing because your skin has extremely high resistance to electricity, but your mouth doesn't, which explains why you can lick a 9v and get a shock but touch a 12v and not feel a thing, and this is more so the case with your butt!
when I get a dildo big enough, I'm gonna put a rumbler from an old controller in it, but only after testing and loads of insulation and hot glue! I probably wont even bother doing that much because the risk isn't worth the extra effort of having a friend buy me a vibrator "for my girlfriend".
have you ever tried Enemas?
