Very Mild Laundry Soap that does not need Softener

[Jayne198]

Elderly mother in law cannot help continually throwing almost perfectly clean items in the washing machine.
Is there a make of washing powder of some kind that does not have to deal with clothes that are not really dirty and does not need a softener afterwards to get the fabric surface soft again ? Thanks

Bold has fabric softener included

a drop of white vinegar is cost effective and acts as a natural fabric softener.