The "experts" on "hoarding" have tried.. just about every measure to sweet-talk ( really, baby-talk ), cajole or coerce a person into discarding their possessions.
They have suggested experiments of the "discard, and see how you feel" kind.
But the one experiment they haven't suggested or tried - remove all sources of stress and unfreedom from a person, remove the real problem, whatever it is.
Remove pressure from family members, especially the toxic ones, the ones doing nagging and yelling - if only temporarily.
Remove space constraints - rent massive amounts of storage, as needed - as much as it takes, to not only store, but properly organize and access the stuff, exactly as it is right now ( sort first, discard later maybe ).
Remove the demands to discard something, most things, everything - just let the person keep or do whatever they want.
Let the person be trully free, let them make their own choice.
And while at it, remove ( discard ) all the bad advice from "experts" ( pathologizing, discard-first, non-scaling organizing advice, refusal to consider alternative solutions, etc. ) - the true garbage and even worse than garbage, as it's actively harmful and misleading.
( I know, I know.. I'm trolling here.. I'm using the same loaded language as they do.. but, it's well-reasoned trolling, I really do mean what I say and I can point out exactly where each piece of their advice is bad )
Instead, give the person some good advice - how to organize, how to decide for themselves without any external pressure or premade decisions.
See how the person fares under these conditions.
Shouldn't they have tried this by now ? They are supposed to be scientists - shouldn't they have tried, and discussed, "the other direction", the "control group", the "keep it freely, and see how you feel" ? Apparently not. Apparently they aren't scientists themselves, it seems.
Well, I have done this experiment - on myself - I know, N=1 - but it's pretty compelling.
The results are, you can probably guess - "Why didn't I think of it sooner ?" and "I'm not looking back !" and "Experts didn't tell the truth.".
"Experts" on "hoarding" are "studying" people in situations where they are under duress, resource shortage and constraints, and they are calling it a "disorder". Even in their books, every single case example is in a situation of resource shortage or approaching it, even onetime well-to-do people. Not a single case where the person has all the resources and knowledge, and still has the "disorder" of "dysfunction in possessions".
It's like studying people experiencing financial failure and calling it "poverty disorder" - these, incidentally, may be significantly overlapping.
Shouldn't they have included examples of successful keeping of all the same materials for comparison ? But then, it doesn't look like a disorder, and doesn't support the claims and the mockery quite as easily..
One also has to ask - perhaps there's a correlation, between all these problems - financial failure, dysfunction in possessions, stress etc. - but who's to say which one causes the other, in which direction the causality goes, and whether all of these are caused by something else, such as an unhealthy relationship, toxic job, incorrect estimation of costs and resources, or what else..
"Experts" on "hoarding" aren't asking these questions, they assume all difficulties are attributable to hoarding, and solvable by discarding.