A dummy is a dummy, empty inside. But... I found a dedicated set of 3D-printed partitions (Partitions for ASG silencer 15924 CZ 75D 150 mm). The whole thing perfectly silences the P-O9, and when it comes to non-blowback CZs, it almost completely silences them! I recommend it—this way, the dummy becomes a fully functional silencer for a total of about 100 PLN. It also improves accuracy. The photo doesn't lie: P-07 NBB, 20 shots from 10m into a 7.5cm target, and I'm no sniper.