White vinegar or lemon juice, let it soak for an hour. Another benefit is they are mild disinfectants.

If you can't get rid of the odor get a new one and keep the stinky one for onions only.

Wash it with soap and water, dry it and put it away. I used a wood cutting board for 20 years...one side for meat the other for veggies. I never smelled it, just used it and washed it quickly with soap and water and put it away.

Argh, what does glass do to your knife edges? These days I use the plastic ones that go in the dishwasher.

-Babka

I will consider all of these and let you know. Thank you - keep em coming.
I have tried lemon juice and of course just plain soap and water. Maybe I will try letting it soak as you suggested above.
Babka, we don't use the glass one too often and do sharpen our knives frequently (because I also do cut directly on the granite )
Admittedly, I do have a very keen (hyper?) sense of smell.

I have a small wooden cutting board that I use exclusively for onions and garlic. All my other veggies and bread, get cut on my large wooden board. Meats get prepared on plastic boards.

I make a paste w/ baking soda & scour the board well, then let the paste sit on it for awhile before rinsing w/ hot water. You might even try letting the paste dry before rinsing....

Wash with hot soap and water as soon as you're done using it. If the odor lingers, pour white vinegar on it and let it sit for 30 minutes.

Also, a glass cutting board is not a good idea. It dulls knives and can cause the food you're cutting and the knife to slip. This is dangerous.