I bought my first pair of these a couple of years ago and primarily wear them as slippers around the house in colder months.  I have washed the linings in the washing machine 3 times and each time they come out beautifully.  They are attached to two metal rivets/buttons and stay in place nicely.  To me, these are the most comfortable Crocs due to the lining.  I just tried to find out if they are recyclable and it is not easy to find out.  Some people donate them to charity if they have life left in them.  Others tack them toe down to a wall, fill with dirt, and plant something in them.  I'm not sure if Crocs is still doing their own recycling.  I checked and they directed me to SolesUnitedDOTcom, but that just took me right back to crocs website.