Because I live in Wisconsin and am "trapped" all winter indoors, I shoot in my basement using a steel 22 cal rimfire bullet trap. While it is effective in containing anything from .177 to .30 cal pellets, it spits out lead particles up to 3 or 4 feet around it. I shoot a lot and am concerned about cleaning up this mess. I've watched videos of homemade traps using wood, cardboard, or plastic boxes with rubber mulch and/or duct seal to absorb the projectiles. How many pellets will these contain before you have to either clean them or scrap them? Do they spit out lead particles or dust? Your experience is helpful.