Lets face it. Most tree species dont root from a bare branch like that. Ill give this sticks 1% chanse of survival.

forget indoors, thas a recipe for a dead plant/tree. Second there is absolutely no need for ( expensive ) bonsai soil, if they root ( big if) and survive you are at least 10 -15years away from something remotely looking like a bonsai. Regular potting soil will do if/when they have enough roots.
I agree with Tropfrog, and diminish it to 0.5% if you want to keep them inside...

0.5% and 1% average out to .75% if I keep them in an outdoor/indoor greenhouse thing. Which I don't have. Take em outside and I have 3 of them so 3%... =[ You guys are no help at all!!!! 10-15 years!!! *Feignts.

lol, don't worry, as I said, try to put on any rough sand you find, no need for especific soil, and just let it be...

They are right, you'll probably loose it, just a few species root from bare cuttings, even fewer on water... But well, we don't know the species, and You didn't know that, now you know...

So consider that an experience gained, if you are really into bonsai, do some research, about suitable species, native from where you live, almost any tree species around you can be trained into bonsai, so you don't need a cutting from a Bonsai tree, you can make them out of seeds/cuttings/seedlings from trees around you, or even find a nursery near you and buy a pre-bonsai...

However, the best time for all this would be spring...