I tried the great suggestion of putting dipes in the sun to get them white. (It worked!!) Then i put them in the dryer for a bit to soften them, but they were still very stiff.
The same is true for any covers or dipes i line-dry inside.
I second throwing a wet (wring it out first!) cloth wipe in the dryer with them for 10 mins. I couldn't believe the difference it made after pulling those cardboard like diapers off the line!! Less than 10 mins in the dryer with the wet wipe and they are nice and fluffy again!
I take my diapers wipes out of the washer and put all the dipes in my pile to go out on the line and my wipes in the dryer. When my dipes are dry on the line, I bring them in and throw them in the dryer with the wet wipes, I dry on high for about 20 minutes and they are very soft!!