I consider them a necessity in all residential applications for the safety and comfort of the bather. Known as a steam diffuser, a steam shield, or a steam guard, they protect by redirecting the steam, diffusing the heat, and preventing accidental contact with the steam head.
Check out this steam guard
which is attractive Teak and lasts a LOT longer than the acrylic ones...
For introducing oil into the environment, we never recommend using the steam head or steam diffuser for safety reasons. Rather, introduce your oil through a spray mist or an aroma pump. I have provided links for both below.AromaMist Aroma OilsAromaMist Aroma Pump