Getting sweat marks out of bedding

[upsoearly]

This is a bit gross... but my husband has not been too well recently and this has caused him to sweat profusely at night. Our (cotton) duvet cover and pillow cases are covered in salty sweat marks which haven't entirely come out after several washes, including most recently with biological washing powder at 60 degrees.

Any thoughts?!

We had the same after dp had flu.

Having consulted chemist sister, I got a container of old fashioned washing soda from the co-op (99p), threw half the bottle in the bath with warm water and left the sheets to soak for eight hours, then put it through the wash as normal.

Worked a treat.

Will try. Thanks!