Vinegar in the washer:
We only recommend vinegar if your water has a high pH (above 9) and if you are going to test your water often.
Added to your wash on a regular basis, it can degrade fabrics faster, especially anything with elastics or with PUL or TPU (this is for cloth diaper users). It can also dry out the rubber seals on front loaders and cause cracking.
Water can, and does change over time, which is the reason for testing regularly. Vinegar has an average pH of 2.4, so using it frequently can create an acidic environment in your wash. In the right conditions, it can be used to soften. However, these conditions are rare. This is why we ask people, as a general rule, to stay away from it.
Epsom Salt in the washer:
Epsom salts in the washing machine can cause rusting inside the washer (worst case scenario).
It can also cause more minerals to be deposited in your clothes from the salt because salt isn’t a softener (best case scenario).
Water softener systems have a separate brine tank that uses common salt to create this brine solution. In normal operation, hard water moves into the mineral tank and the calcium and magnesium ions move to the beads, replacing sodium ions. The sodium ions go into the water. When you add salt directly into the washer, it’s not the diluted solution that you get with a whole house softener system.