+2 on that. The "Chain Swapping" technique you describe is precisely how conscientious riders of yore were supposed to do it. Are you planning on using the big old school tin of stovetop Putoline described in this old thread here?: https://forum.classicmotorworks.com/index.php?topic=30792.msg368178#msg368178 (with my own postride gear oil swabbing regimen and "equipment" described earlier in that thread).
Also, would you care the share that source for the $9.95 chains you mention, and let us know how you get along with them? I may be having some success with my own single-chain technique, but I also know I might do well to sock a pair of chains away for "later" to do it properly.
Yes, the pan of hot grease is what I'm thinking. I haven't decided what grease I'll be using yet, gonna see what possibilities exist.
I found inexpensive NOS chains from BMIKarts & Parts, in Versailles, Ohio.
https://www.bmikarts.com/Vintage-Motorcycle-Parts I've bought from them before, some silencers via Ebay, and was pretty happy with the quality and the price was amazing. They apparently buy up old stocks and sell them, at very friendly prices.
I was wrong about the price though. The 530, 104 link chains that were originally intended for use on Harley XLs, 50 years ago, were $5.00 each. Shortened suitably, I think that these will work great on my C5 UCE, on my '70 CB 450, when that someday comes back from the basket, and with the 1/2 link that BMIKarts also sells, on my '99 RE IB too. Maybe you will want to spread the word to the IB crew? I could see our IB guys as being receptive to standard chain, and not put off by the idea of knocking off a few links.
Regina is an Italian chain maker that has been making link chains a long long time.
https://www.reginachain.net/I anticipate these NOS chains to be decent to good quality, made of hard, carbon steel.
BMI is also selling some Takasago ( RK & TK ) chains, and some from TIDC who I understand made the "Saphire" and "Diamond Super" brands.
https://www.tidcindia.in/Diamond_AC_AutomobileDriveChains.html I read that TIDC had some technical direction from Diamond Chain company back in the 1960s, but I don't know if there is an ongoing relationship. I consider Diamond (USA) to make a top quality product, and it's a shame that TIDC is able to market their products with the diamond logo. I think this has really diluted the perception of quality associated with Diamond. A TIDC "Diamond India" marked chain came installed on my '99 IB. I think that was the OEM equipment. It's decent quality, but not equal to the US product, in my opinion. BMIKarts is also selling what looks to me to be NOS, USA made Diamond chains.
The Regina chains are most attractively priced. Imagine what BMIKarts must have purchased them for, if they can make a profit selling NOS chains for $5. That's 1950s pricing! If someone is interested, I'd suggest acting now. BMIKarts is a closeout kind of vendor. Sale priced stuff sells fast.
One thing that non-Oring chains can definitely do better than O-ring chains, no contest, is sit in a box on a shelf for decades. This source says Acrylonitrile-butadiene, (which is the material most used for many, if not most chain O-rings, has a suggested shelf life of 5-10 years.
https://warco.com/resources/storage-conditions-shelf-life/ If they can only be expected to last that long on a shelf, what can we expect if they are exposed to the elements that attack them. According to that same source, those elements include "Ketones, Ozone, Sunlight, Aromatic Oil, Flame, Weather".