If you mean the eggs that are about the size of large hen's eggs, those are much larger than I can use. The Kinder Egg capsules are about 2" long x 1" diameter cylinders with rounded ends, just about exactly right to fit my miniature plush squids.

The glass beads I used for my prototype made a reasonable amount of noise against each other, without having to bounce off a hard wall. The pill bottle I used in the prototype was of a moderately hard plastic -- HDPE, I think -- and was probably only a bit more rigid than the Kinder Egg capsules are.

I'd have to go looking for the vitamin C tablets to know exactly what you mean, but I suspect that the tube is probably not a good shape, and that I'd be paying a fairly stiff price for a package whose contents I'm not interested in.