I have used a similar process with success. I bought a few bottles of silver craft flakes and minced it to dust. I then brushed a layer of polyurathane into the groove to hold the dust and then compressed it down. I repeated this process a few times until I reached the timber level.
I found that a light finishing sand over the entire surface did not dull the poly and it looked for all the world like a polished steel rod embedded into the timber.
I used to make '21st' keys and coffee tables many years ago. At the time it was very impressive.
Don't know if this is any help, and good luck.
Of course I'm brave, I'm afraid of NO man, and only a few women.