how to downgrade a gem?

I accidentally leveled a gem to high (after switching my amulets i realized i'm 2 dex over the limit). I could have sworn that using a scouring orb on a gem will downgrade it, but that didn't work. Is there a way to downgrade a gem by 1 level? Or is my mind playing tricks on me (i swear i read it somewhere in the forum). Is it a sign that i should rather downgrade my drinking?
Please help, i have to make a decision (looking at you sixpack).

There is a recipe using orb of scouring and a leveled gem that should give you one level lower gem as a result. All you need to do is to "sell" the orb and the gem to a vendor.

Thanks a lot. Hope my memory will recover once i stop drinking.