How do I disable post-processing at runtime?

On the advice of another thread, I used the name space UnityEngine.Rendering.Universal and called the following on my scene's main camera:

 mainCamera.gameObject.GetComponent<UniversalAdditionalCameraData>().renderPostProcessing = false;

This successfully unchecks the Post-processing box for the camera in the inspector--however, this appears to be a purely cosmetic effect, as it does absolutely nothing as far as actually disabling post-processing effects in the scene. Surely there is some way to accomplish this?