I went to some antique stores yesterday and investigated some used vinyl record bins. My unscientific research on most purged artists from private record collections:
1) Molly Hatchet
2) Barry Manilo
3) Captain and Tennille
4) Jethro Tull
5) Iron Butterfly
6) Bill Cosby
These artists are the dregs of the bins. If you find more than one copy of these in a bin, just move on. I think they multiply when kept in close proximity.