My ds's have LL Bean backpacks that are both 3+ years old and I have never washed them. They took them to camp for 2 weeks and they are so filty they have to get washed. Can I put them in the washer on delicate and air dry? I'm worried they'll get damaged but spot cleaning will not do the job here.

and it's 7 years old this year
Never had a problem.
She carried that backpack from 3rd until 8th grade but adamantly refused to go to high school with it. It has been washed countless times with Oxiclean and laundry detergent using warm water and the regular cycle. I hang it to dry. That darn backpack still looks brand new. They are indestructible or at least they were in 2001.