Allen, the crownbees website is awesome! Thank you for directing me to it. It does bring up some questions though.
As far as 'harvesting' the larvae, I don't think any of the people coming to my workshop will be up for that. They're all hobby gardeners and at this point I'm doing good to convince them not to use a bunch of chemicals in their gardens. I'm wondering, will it be OK to not clean out the mason bee tubes?
Crownbees also says to not use bamboo, but that's what I have available. So now I'm wondering if I should just do another project all together? The insect hotel seemed fun, simple, and useful. I don't want to overwhelm novice gardeners, but I also want to do it right. Looks like I have some decisions to make. Thanks again and thanks for the welcome!