beemandan,
That is a great idea and it could save some fingers! Try to stick with the 2 by 6 for depth; a 2 by 4 is a little shallow and you will get fewer females. Also, I still recommend the tape around the seam to keep pests out. I’m glad you are going to have fun with it.
Omie,
The tubes are easy, clean, and fun. It is entirely up to you if you want to unroll a tube and inspect the contents or not. There is no cleaning of the block, just replace the tubes during the winter. If you just drill a block that will work fine the first year or two and then they get fouled and the bees won’t use them. It is easier to drill the holes and just put them up. If you have a supply of blocks and wish to use them for one season and then replace them you’ll do just fine. I actually have two large blocks that I’m going to destroy after the bees emerge; they must be 2 and 3 years old.
Regardless put some up and have fun.