I believe the silicone used for aquariums is the most inert and stable sealant you can buy. The most likely source of failure when using it would be where it adheres to the glass itself, so you'd need to be certain everything is as clean as can be. Also, silicone doesn't like to stick to itself, once it's skinned over, so only caulk these joints once and make sure the seal is as good as you can make it. Even if the silver solution does eventually break down the joint (which I truly doubt), there is no better option short of fusing the glass.