Marc,
First of all,I'm not a pro,but I have had some success.
In all the written material I've found (so far),rooting hormone was not very effective for Blueberry cuttings propagation.It probably won't hurt,but what is more important is having a film of water on the leaves until roots form.
I use a Mist-o-matic and also a box with a timer and a pond fogger set in a tray of water,surrounded by the cuttings stuck in a peat moss/perlite mix.
The pond fogger method works fairly well and is shown by a guy on Youtube.
Are your cuttings from Winter pruning or new growth in Spring/Summer? Brady

Brady,
Thanks for the ideas on the setup for rooting. I may give that a try for summer cuttings. Based on posts by tc88 and others noting success with late winter cuttings, I'm planning to try some this week. The plan is to make a wedge or long slice cut in the stick, apply hormone, place it in a mix of pine bark and peat, then leave undisturbed in an unheated barn until spring. Then shade and occasional watering. We'll see. Your observations on the ineffectiveness of the hormone are interesting.

Thanks,

Marc