Just adding some more, I'm looking on amazon and the best selling one, in the reviews, people were having lots of trouble. One guy posted a video of a carpenter bee trying the home though! (but it got stuck because the holes were too small)
So we are making progress everyone! I just need to do a few more hours of research on the matter apparently...
Edit: This is the only product I've found on Amazon with more than 0 reviews saying they were successful in getting carpenter bees. There are still lots of comments saying it didn't work for them, but one or two people said it actually worked.. and so I will be trying it.