About a decade ago,, I used a totally different approach to carpenter bee control,,
I figured the bees probably like sugar,, so I dissolved sugar in water, and mixed in some malathion,,
using a pump-up sprayer, I sprayed the inside of an old wood shed that the bees had been having their way with,,
The bees were 100% controlled for that year,, I repeated it the next spring,,
we did not see a carpenter bee for 3-4 years after that,,
I am sure other insecticides would work, I just happened to have malathion available,,,
I thought about putting the same mix in a humming bird feeder,, and hanging it in the shed,,
never got around to trying that,,,