Bass traps do have material designed to absorb sound energy, but they are engineered for specific frequencies. A random size mat will maybe absorb one certain frequency if you're lucky. Likewise, the spacing on the corrugated side is fixed. That means it will affect different frequencies in different ways; scatter some, reflect others. If your only goal is to prevent sound from traveling through the drywall, the mats may help, but they will make an acoustical mess inside the room. Acoustic panels are not new science and have been around for decades. There are reasons that they are designed a specific way.