This is quite true. Very little established science requires classroom experimentation to learn. Even at the higher levels. I'm in medical school, and I almost never attend lecture. I generally only attend the classes that are involved in teaching me elements of the physical exam and other forms of interaction with patients (those are skills that genuinely must be performed in order to be learned). I make better grades than most folks in my class.
I agree with your point about how classroom "experimentation" is merely repetition of a set of instructions. From personal experience, all through high school (and the first half of college), I really didn't find that they helped me understand the principles any better. Students follow the instructions without actually knowing much of why they are doing what they are doing. As a result, they actually learn very little. However, I must say that that is purely my opinion.
I see home-schooling as a way for children to obtain a far better education than that which they receive in public schools, and perhaps even some private schools. My husband and I are considering home-schooling our children, but it's going to be several years before we start having to worry about that. In the classroom, students are limited in their pace of learning by the slowest and most disruptive members of the class. While I took advantage of the opportunities I had in school and learned well, I do sometimes wonder how much better educated I could be if I were able to learn at my own pace and not someone else's. Not to mention the fact that, in school, the student is subject to the teacher's agenda. While I myself am a bit of a fan of Darwin, I came to feel (after doing my own reading) that his theories were conveyed to me with the intention of my adopting a specific viewpoint.
And when I was the age of your children, I did not know what a double-blind experiment was, either. Kids their age generally do not study psychology. So I think you're doing just fine.
But kids are exposed to ads promoting medicine, and TV shows promoting the parnormal. The concept of the double blind experiment is an aid to getting through life.
You can get through life without knowing geology or astronomy or much about chemistry. But junk science confronts everyone everyday, invades their politics and takes their money.