They wouldn't allow the lead bag to go through without inspecting its contents... which could be anything, really, including weapons. So it's pretty useless. Just a clear plastic zip-lock bag works well, I've found. And the inspector ladies who tore the wrappings off every one of my rolls of 220 Fuji film (NPZ800) probably expected me to chip my gums at them over the delay, but I just thanked them for their careful work. Grrrrr.
If you reuse commercial 35mm cassettes, then there's nothing to alert the inspectors. I haven't done this, but some have suggested just taping the end of the fresh bulk length to the 1/4" or so of film sticking out through the felt lips of the cassette, so it never needs to be popped open. I have only reloaded Agfa and Ilford cassettes that can be opened without damage, and reassembled over and over.
If you reuse commercial 35mm cassettes, then there's nothing to alert the inspectors. I haven't done this, but some have suggested just taping the end of the fresh bulk length to the 1/4" or so of film sticking out through the felt lips of the cassette, so it never needs to be popped open. I have only reloaded Agfa and Ilford cassettes that can be opened without damage, and reassembled over and over.