Does ProGold have a shelf life?

Bombay, the chemists would probably disagree with your read on this. How can you say the chemical components have not broken down and become useless? That is pure conjecture. Everything has a shelf life.

Ok, Swanny76109, it's now your word versus mine!
You say that I have not done a chemical analysis so I'm hand-waving.
I say that neither have you & so you cannot confirm whether the chemicals have or have not broken down.

Sure, the chemists would disagree with me - they are chemists & they are trying to be exact. Plus, if they are Caig chemists they a$$ is on the line if they do not take the conservative route & say that after the shelf life the product is pure garbage. (BTW, this tack also helps their sales!).

This is a simple matter that, I feel, does NOT need an argument!
Let's say that the chemical did breakdown. So what?
I say that it will still clean but NOT as effectively. Now, it's up to the owner to either throw away the bottle OR buy a new one.
If you do not believe this rational (& you are free to disagree) then I believe that the onus is on you to prove otherwise. If I'm wrong I'm willing to change my stance.

Some analogies come to mind: I throw my food away when the freshness date has expired. I throw my prescription meds away too. My used paint in the garage usually starts to get funky and mucky after a couple years sitting in the can. I also change my oil every 5000 miles since the oil breaks down and doesn't protect my engine as well and I want my car to go for 200,000 miles or so if I can get away with it. But, that is me. Not looking for an argument by any means, but I still say everything has a shelf life. I think the majority of rational people would agree with me here but you can agree to disagree, that's what the forum is for. Cheers!

One thing that got missed here too: the original poster was concerned about the time it took him to do the work. If I spent a bunch of time cleaning my equipment like he did and realized the product I was using might not be as effective, I'd be bummed too because my time would be worth so much more than the value of the chemical here. It's like when you choose a 20 year paint or a paint without a warranty. Why not spend a bit more on the quality item and do the job right and be confident the paint won't be peeling away in 5 years?

04-01-09: Swanny76109
Some analogies come to mind: I throw my food away when the freshness date has expired. I throw my prescription meds away too. My used paint in the garage usually starts to get funky and mucky after a couple years sitting in the can. I also change my oil every 5000 miles since the oil breaks down and doesn't protect my engine as well and I want my car to go for 200,000 miles or so if I can get away with it. But, that is me. Not looking for an argument by any means, but I still say everything has a shelf life. I think the majority of rational people would agree with me here but you can agree to disagree, that's what the forum is for. Cheers!

Your analogies are good in & off themselves (& I have the same mode of operation w.r.t. car oil, paint, etc) BUT I think that the gravity of the situation for car oil, paint is much different from cleaning connectors in audio. So, I think that the analogies are not directly applicable.
Indeed you are correct - if you use bad motor oil the risk of engine breakdown & loss of use is a high penalty. OTOH, if you clean connectors with old Caig ProGold, the penalty is not high in comparison.
If you use old paint in your house, the penalty that your interiors look bad is a high penalty. OTOH, if you clean connectors with old Caig ProGold, the penalty is not high in comparison.

One thing that got missed here too: the original poster was concerned about the time it took him to do the work.

I re-read his post & saw that he was talking about potentially wasting effort - Wasted effort & time for that wasted effort.

Why not spend a bit more on the quality item and do the job right and be confident the paint won't be peeling away in 5 years?

As I wrote in my prev post - it's up to the original poster to determine what he wants to do. If he thinks that his time is worth much more than the chemical(s), sure, go ahead & buy a new product.

(Just a side comment here - if all of us claimed-audiophiles (myself included) REALLY thought that our time was worth a lot more, we should not be in this OCD hobby! The time & things we fret about is, often, ludicrous & head-shaking!)