Glass toys

Something slim/skinny and with very little texture. Glass feels bigger when inserted due to its unforgiving/non-squish y nature. The texture also feels much more intense on glass than other materials. I would suggest going with something a little smaller than you normally would get, and virtually completely smooth. Some of these could be a good place to start for a beginner to glass.

probably the rainbow nubby would be best

I would somthing kind of skinny, that doesn't have a lot of designs or raised stuff on it.