Well, let me see if I've got this right. You are willing to take "on faith" that boiling snares in baking soda weakens them, because you read that somewhere. Now, in order to convince yourself it's not, you require that someone "show" you it's not harmful? Don't you think your requirement for proof is a little lopsided?
I ain't no Wackyquacker, but I can science a little bit.
For starters, yes you can overdo this. I did one time. I had a whole box (one pound) of baking soda that was clumped up, so I just dumped the whole thing in a gallon pot with some snares and boiled them about a half hour. I don't think the baking soda at the bottom of the pot ever fully dissolved. I had a concentrated solution. Long story short, some of those snares, especially those that had coils laying near the bottom of the pot, did start to rust after a short time in the field. I had to throw some of them away.
If you boil snares in baking soda, you don't need any more that 1/4 cup (That's 4 Tablespoons) to the gallon. You are doing two things here. First, you are cleaning the snares, and removing the oily smell from the cable. Secondly, you are instituting a chemical reaction on the galvanize coating on the wire. You are making oxides and hydroxides which are a dull gray color. That's why the cable gets dull.
Where I went wrong earlier was to make a highly concentrated
caustic solution. Granted this is hard to do with plain old baking soda -- but I managed to do it. In this state, instead of forming the oxide/hydroxide coating on the surface of the galvanization, the solution attacks and removes the coating. The steel is exposed and rusts quickly. That's why it is not a good idea to boil snares in lye water. Lye is a very strong caustic.
But back to the point. Boiling your snares is a dilute solution of baking soda is not going to weaken them to any degree that would be measurable to you. As for them rusting from the "inside out" I don't see how that’s gonna happen. There is not going to be enough residual baking soda "inside" the cable to do any harm.
Really, this baking soda bath is little more than to speed up the process a snare would incur in nature. Even if you hang a brand new shiny, untreated snare, it is going to dull up on its own in a few weeks. I wouldn't worry about a baking soda bath causing premature failure of your cable.
But while we are on this subject. I can not recommend soaking or dunking galvanized snares in vinegar or any other acid for that matter. Acids go "straight to the throat" on the galvanizing material. They don't form any coatings, they just eat straight away at the galvanizing. (And I hope that doesn't confuse the issue.)