@Montegut I think you have to answer for yourself two questions:
- are your siblings thoughtless or actually selfish?
- what do you want to accomplish?
The actions you might take are very different depending on the answers to those questions.
If your siblings are thoughtless, then you can wake them up with a plea for action. If you have already made the plea clearly and in writing (not just hinting) then you can send the “Time to finalize” letter.
If your siblings are actually selfish, then your boundary is easier to establish and hold to because what are these people bringing to your life?
But before that, What do you want to accomplish? is the question to answer.
If it is simple (clean out and not pay for storage locker), then there are many good suggestions here.
If it is complex (I want my siblings to care that I cared, to show their love of me by x, y or z) then you must know that you can’t control other people. You have to resolve in yourself what the stuff means and what being a sibling means. Sometimes we need to create a family of the heart and let the family of blood become “acquaintances” .
I lived through the cleanout of Mom’s house and finally processed internally to myself that it isn’t about the stuff it is about the actions. And accepted control of my own actions and let all the other people have theirs. THAT is TOUGH, but eventually, it is a lot more peaceful.
Full disclosure, my sibling and I totally get along, we have a good relationship, but he was unable/unwilling to take much action to clear stuff. In the end, yes he hauled a bunch of stuff home to his house and my husband stood behind me with a pitchfork so I didn’t take much. 3 years later, I am grateful to DH, but don’t know if bro is mad because HE has the stuff.