Like this one. You'd probably be surprised at how much misting this can take before the underlying substrate gets wet. I've pulled the moss aside many times to check on a fair number of trees with the same treatment. This one is full of growing tips now and shed a lot less foliage than I'm used to seeing so it seems like a promising method.

Sorry the pic sucks, it's all I can do with the devices available right now.

I have a layer of thick loose moss covering the substrate of a fee spruce and firs, this is to keep the substrate moist without having to drench the mountain soil rootball too often. Moss keeping the lifelines moist on just 2 junipers.  I don't know how long I will leave it, tempting to remove it now that they are actively growing mostly because the trees are more fun to look at without covering. Possible problems with leaving it could be hiding boring beetles which so far I haven't found in my yard but the cause of death of many great old trees where I collect and maybe it could lead to fungal issues. So undecided when to remove it for now, first year doing this.

Thanks John,

I've never used anything yet, after about 10 years of keeping and collecting yamadori I have only once found an active borer and poking a sharp bit of wire down the holes took care of it.
I have recently paid a bit more attention to dead and dying trees in the wild though and it does look like  borers are having a pretty big impact, especially with narrow lifeline junipers it doesn't take much to cut of the flow. I'll take note of the product mentioned for sure and consider preventative use.