Plenty of people put condoms on their sex toys to keep them clean and safe, and in fact condoms are handily designed to accomodate just about anything with which you could care to penetrate yourself. The logic works backwards sometimes too: just about anything you put in a condom becomes something you can penetrate yourself with. Cheap as free sex toys for every occasion! And you get to give them your own silly names!
I've experimented so that you can experiment better.
Inspiration: A fascination with collections of small things.
Construction: A latex condom filled with mixed whole grains and tied off.
Results: Great texture, but not much backbone. To get something more like a phallic stress-ball, I used two condoms with lube in between them. With double latex, this is a worthwhile creation, but the outer condom is prone to breaking near the knot.
Construction: Cooked chocolate pudding poured into a strawberry-flavoured latex condom and chilled to set. I used half the liquid called for and hung the filled condom inside a cardboard tube while it was chilling.
Results: Hmm, pudding. It worked better than I thought it would, holding its shape quite nicely, but would really only be a functional toy for someone who fetishized flaccid cocks. Perhaps it could find some kind of non-penetrative use it feels much like a guys' masturbation sleeve. Alternately, a more solid core could be embedded in the center (e.g., banana?), and surrounded with pudding.
Inspiration: The need for something tougher than pudding.
Construction: A latex condom filled with smooth pebbles.
Results: Pretty good! Provided there is one larger pebble at the end, this contraption is easy to manoeuver. The pebbles aren't just bumpy, they move around. This would be a fun Kegel exerciser!
Inspiration: The possibility of a curvy toy.
Construction: Modelling clay shaped into a pensive brontosaurus neck, wrapped in a baggy latex condom.
Results: Using clay doesn't really uphold the spirit of this experiment, since it would hold its shape without the condom (indeed, the condom is hanging off the clay frame), but it was worth cheating for. Fully poseable and satisfyingly heavy.
Inspiration: The multiple ways to transform one-dimensional string into 3D objects. Mainly knitting.
Construction: Bunches of unknittable blue yarn stuffed into a latex condom, with a few artistic ropey bits around the sides.
Results: Disconcertingly light, but otherwise remarkably functional. Probably the most thrustable of all the experiments, with an athletic, springy texture. Easy to reshape. With more twists of yarn, this could be a very textural toy.