How to Use Vinegar in Laundry (and When It's Best to Avoid It)

Vinegar functions as a laundry sour ... acidity to counteract the alkalinity of detergent. Sours go in after the detergent is gone ... so in the rinse, the last rinse.

Some frontloaders dispense chlorine bleach into the first rinse. Softener dispenses into the last rinse whether frontloader or toploader.

Note that fabric softener products contain lubricants which vinegar does not ... so vinegar doesn't function as a softener in that respect.