* commercial canned foods have enough heat treatment to kill nine log cycles of spore forming bacteria. Plain cold water washing removes five log cycles of contamination and adding soap to a cleaning solution increases this to six log cycles of bacterial reduction. Non spore forming organisms like E. coli are easy to kill ex # let them sit wet for three weeks at room temperature # heat to 140F for 30 minutes # heat to 160F for a minute , (wet heat is more effective than dry oven heat) ,,,, your bottles are pretty close to what industry (FDA rules) called sterile just by using soap water
* wine is a preservative system, I don’t worry about food poisoning organisms above 5% ABV and pH under 4. I tend to have severe enough conditions to kill most wild lactic fermentaion pH 3.3 and 11% ABV and no oxygen in the headspace. Your main risk is oxygen consuming organisms as Acetobacter (make vinegar which is edible) or molds (make yuck flavors / make snot like slime / make cute colored fuzzy colonies). From a health point of view, keep the air out and don’t worry.
* there is probably more contamination on any natural cork than on the bottle or via the wine. Curious, do you boil your corks? Commercial practice is to dump a case in the hopper without any treatment. I use synthetics (Nomacork)
* A lot of cleaning is cosmetic to remove floating material , , , , on the positive, boiling might make it easier to clean mold gunk, likewise soaking with PBW or one step would make it easier to clean. If the bottle doesn’t look clean I don’t use it. This is mainly because I like pretty low turbidity beverages.
* in the micro lab sterile bottles and tools are stored for years in aluminum foil. In the micro lab we buy sterile plates and they remain sterile as long as a cover is over the plate to prevent dust from falling in. ,,, I store bottles mouth down
* this is so far from what traditional alcohol beverages look like, or modern jail house hooch.
Industry runs tests as canned food will be incubated at 30C to see if anything (spore formers like clostridium) will grow. What organism has been creating your historical problem?