A_SuperFireShot, and A_SuperTurretFire are variants of their non-super counterparts that can repel SuperSonic, though they don't deal any true damage. There's also a Flags2 value that can make any missile able to repel SuperSonic, though again, that won't take away any rings.
If you want to drain rings, it IS safe to use A_RingBox to drain one ring at a time, while the player is in a completely hostile enviroment. (Like underwater in a pit of acid, NOT like Mystic Realm)