Just for the record, technique, safety, and other firearm skills were taught to my kids years ago on the BB gun.
It is not the same, but it was the teaching platform we started on. Living in Suburbia, it was something we could do often in the back yard. It allowed them to demonstrate safe handling prior to the first firearm.
Under some circumstances that is the only viable solution but often an imperfect one. The BB is ballistically unstable in flight and thus inherently inaccurate. It does have awful bounce characteristics and the old tale about shooting one's eye out is unfortunately based in fact. Where I had a choice when a "real" firearm wasn't available I would go with a .177 air gun or a .22 airgun that was pump operated instead of the old style spring driven BB. But it is incontestable that you have to work with what ya got not what you wish you had. I'm glad you were able to impart the basics safely with the venerable BB.