CRT Vacuum Release Made Slightly Safer

So, after harvesting a CRT monitor for parts, I was left with the tube itself. The final step was to break it so that air could rush in, but the danger of explosion made me nervous in a small apartment. Then I had an idea - I had a bunch of large plastic tubs sitting around, so I put a large scrap of foam (from a mattress topper) inside, placed the tube screen-down inside, and used a hole saw to make an opening just slightly larger then the tip of the tube in the lid of the box. With the lid on, I put on heavy gloves, goggles, jeans and heavy long-sleeve shirt, and crouched behind a deck chair. Used an old screwdriver and a rubber mallet to shatter the end, and all was well. In the event of an implosion, the plastic wouldn't stop all the shrapnel, but it would at least contain the worst of it. I hope. Any thoughts?