Bubbler is a great idea. I've had good success with 'em before. I only use a cup of water because I adjust daily already and I appreciate the simplicity.
Rooting without hormones has about a 1 in 8 chance of success generally.
I said it before, but I'll say it again, I don't use hormones anymore and I very rarely lose a cutting. I know other growers who don't use hormones either.
Honestly, I don't think rooting hormones are necessary at all for marijuana. In fact, it's been my observation a lot of 'em (particularly the powders) will actually slow the rooting process.
That being said, I do hear good things about clonex. But I've never used it, too expensive compared to my magic tap water.