I remember years ago seeing anti corrosion bags for guns at sportsman's guide. Just searched there and can't find them.
Does anybody know where to get something like that? Do they work?

Umm....Amazon?

https://www.amazon.com/Zerust-Anti-Corrison-Rifle-Zipper-Closure/dp/B00PM1GI62/ref=sr_1_2?dchild=1&keywords=anti+corrosion+bag&qid=1590226558&sr=8-2

Yes, they work and work well.  
This is how the military now stores weapons.  The rifle can be removed from the bag, wipe out the bore and apply some fresh lube and it can be used immediately with none of the old grease removal problems.

Brownell's sell good ones............

https://www.brownells.com/gunsmith-tools-supplies/shop-accessories-supplies/gun-storage-materials/gun-storage-bags/vacuum-seal-storage-bags-prod42749.aspx

You can also make your own with Gun Wrap vapor paper and special plastic bags.....DO NOT use standard plastic bags, the plastic used will pass moisture and allow the protective vapor to escape............

https://www.brownells.com/gunsmith-tools-supplies/shop-accessories-supplies/gun-storage-materials/gun-wrap-paper/gunwrap-paper-prod1197.aspx

https://www.brownells.com/gunsmith-tools-supplies/shop-accessories-supplies/gun-storage-materials/gun-storage-bags/triple-tough-premium-storage-bags-prod1154.aspx

I've been getting mine from these guys for years.  

http://www.polygunbag.com/gunbags.html

That looks like what I want. thanks.

No problem. My only issue is that it's a small family owned buisness so sometimes they can be hard to get a hold of or call you back at certain times, but it always has worked out.

Amazon alone has a bunch of different brands & sizes.


https://www.amazon.com/dp/B00SEMQQPY


https://www.amazon.com/dp/B00A2THDSQ


https://www.amazon.com/dp/B00SLZFFCY


https://www.amazon.com/dp/B012EIXSCW


https://www.amazon.com/dp/B001O45FR4


https://www.amazon.com/dp/B00SLYY5DA


https://www.amazon.com/dp/B001O47HKW