Does anyone have a magic solution to apply to a zipper that has become impossibly stuck? I have tried, baking soda, bleach, hot water, etc. Thanks.
If plastic (if not time for a new PFD from this century) - it's unlikely a salt issue, and water rinse/soak would fix if it was. I leave mine salty all the time with no issues.
A. Broken/pulled tooth (PFD zippers normally being the large tooth style vs. the self healing coiled style) - and made worse trying to force it open - or...
B. Some debris causing same hangup/jam issue.
You should be able to carefully work the slider past the trouble spot (whichever way it will go so you can see the problem spot). Some 303 or a lubricant that won't make a mess may help.
Have you tried a bit of WD-40 ?
If you do and you get it working than use some silicon spray on it.
It may not be just salt, maybe some small grit in there too if the usual solutins aren’t working. Have you tried using something like a power washer or a lawn watering hose end that can concentrate some soapy water and really force it thru the teeth?