Hmmmm! I had five full metal boxes that you store slides in. I solved that problem very easily. I took them to the landfill. I did not want to sort through all those slides!! I have a similar, but worse, problem with negatives and I have a feeling they are going to go the same route.
A lot of years ago, I TOSSED all the family photos of relatives I could not identify. If I don't know who they are it really doesn't do a thing for me to have the photos.