I did the initial clean out in 2014 after my mother died, and kept going through drawers/closets each time I visited my father. On one visit I cleared a freezer - vegetables my mother had frozen in the early 1990s. It broke my heart to see the waste.
They had lived in the current house since having it built in the late 1990s, and when they moved in, the accumulated crap from house #1 (build/lived in since the late 40s) was shoved here there and everywhere, including the huge basement. Some of that never got unpacked. I found old coins, 2 pistols (thankfully unloaded) and all sorts of strange things intermingled with the old magazines, coupons, cards and who-knows-what in boxes. We had to pretty much check everything, which is how we found the money. Not a lot, but good thing we didn't toss the boxes under the assumption that if it hadn't been touched for 20+ years, there would be nothing of value.
It was sort of interesting when I uncovered papers during the initial sorting in 2014, but after a while, it was just drudgery.