I use motherease airflow wraps for both my kids, but they are starting to smell of urine, even after washing. I usually dry pail my nappies and then wash them at 60C. The wraps are either thrown in with the nappies (not dry pailed) or washed at 30C with my other laundry (unless soiled). Any suggestions as to how to get rid of the smell? Should I soak them in a water and vinegar solution? Thanks!