Re: If you too have well water, and a softener, please help!
I think I've answered my own question - so I'll post a reply!
Even though I have soft water, I decided to strip my pocket diapers & inserts with Calgon (on pinstripes and polkadots they recommend that Calgon can be used to release residue and is good for removing optical brighteners)
LOADS and LOADS of SUDS came out. It looked like I'd added a whole cup of detergent to the wash.
To make sure that the suds were not Calgon suds, I dissolved some in my mixer bowl and whisked on high for a few minutes. No suds, so the suds in my washer really were detergent residue, not the Calgon (I also cleaned the washer out with vinegar prior to this experiment). Then rinsed, rinsed, rinsed.
After taking the diapers out of the washer, I hand rinsed in hot water to double check for suds, but they were good.
I've been at it all day, but I decided to devote today to scientific experimentation, rather than the haphazard changes to washing routine I've done before.
So now my diapers are stripped and as soon as DS's rash clears I'll start using them again.