Actually because of Envirotabs, Slick 50, fuel line magnet, tornado, hydrogen generator, and other products I've bought, my fuel tank actually fills as I drive.

I have also read to use a mixture of hydrogen peroxide and boric acid.Not sure what to do at this point.

The two most common elements in the Universe are Hydrogen .... and stupidity"

If the problem is to remove sulfide compounds, and I've found mention of "carbon disulfide, carbonyl sulfide, hydrogen sulfide, and strontium sulfate (trace levels" as the possible culprits in this drywall, then removing them is a somewhat understood process.

Hydrogen sulfide is toxic but may not be a health hazard.

If you aren't yet using the Steri-Mist device, sold by TOMI, to apply ionized hydrogen peroxide to walls, etc., in hotel rooms, to kill any residue COVID-19; then you might consider this device.

You can actually try hydrogen peroxide but it will affect the color of the wood. 

And it ionizes hydrogen-peroxide, into a mist, that kills germs.

@Shantan Kajjam The odor is Hydrogen Sulphide which is released it the process.

Hydrogen peroxide will kill it just like an infection on a scab.