Horn silver treated with sodium thiosulfate reveals new details!

I have this intermediate tetradrachm in my collection for a few months now, I got this from Brian Bucklan for really cheap, thanks to the horn silvering.
I did not try to remove the layer as I was scared of damaging the coin, But after my recent addition of a classical owl I decided to give it a try.
So I soaked the coin in a warm solution of sodium thiosulfate for 30 min, and repeated it for 3 times with a bit of washing in between.
This really got rid of most of the deposits, but left a lusterless darkened coin, and to correct this issue, I cleaned it with sodium bicarbonate which got rid of the darkness and also restored some shine.
This is the before image,


After image,

Intermediate tetradrachm
Pi-style V
c. 350 - 297 B.C.
I'm really surprised to see the amount of details hidden under thick layers of horn silver, especially the tendrils on Athena's helmet (which really helped me attribute & date my otherwise generic tet), and also on the reverse the legends AΘE really popped up along with the detailed feathers on the owl's head and breast.
Initial mass- 16.9g
Final mass- 16.57g, nearly a hemiobol level loss in material, although I'm happy to trade it for the gain in details.

 

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Holy cow! The detail that came out is great! Totally worth the loss in weight IMO.

 

Dramatic change.
I have also experimented with sodium thiosulphate, but the only visible results were for coins with dark patches i.e.

 

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