[1.7.10]Create explosion that does no block damage

Hey, title says most of it. I'm trying to create an explosion that will not damage the environment (only damage the player, play sound, create particles). I'm trying to do this under certain conditions for creepers. According to the documentation of the Explosion class, doExplosionB() should do what I want. This is what I have right now:

@SubscribeEvent
public void onWorldExplosion(ExplosionEvent.Start event)
{
    Entity cause = event.explosion.exploder;

    if (cause instanceof EntityCreeper)
    {
        event.setCanceled(true);
        Explosion explosion = new Explosion(event.world, cause, event.explosion.explosionX, event.explosion.explosionY, event.explosion.explosionZ, ((EntityCreeper) cause).getPowered() ? 6 : 3);
        explosion.doExplosionB(true);
    }
}

However, I must not understand the consequences of using doExplosionB() without doExplosion(), because this does not work. The creeper disappears and no explosion is created.