My procedure would be
-open tin
-if its garbage like those couch feet go directly to bin
-maybe spill some on the hand like you did if there is a lot inside, make a picture
-close tin
-put a number on the label
later rename pictures to numbers, render all in a html page in big clickable grid, this way you (or assistant) can asses in 5 seconds without getting up.
Im guestimating you will be left with ~20-50? tins of actually usable stuff.
I used to be a hoarder myself, nowadays its under control (thats what I like to think), most of the crap is in the basement or boxed waiting to be thrown away.
Around my bed currently:
Boxes are all full of old projects, pcbs, power supplies,cables etc.