My guess is that she wants people to do this as quickly as possibly- and that means NOT hanging onto joyless possessions so you can sell them "someday" or "when you get around to it".
I'm also reminded of what FlyLady said when confronted with a similar situation (she says to bin things a lot and was asked why she didn't encourage people to recycle): "I don't know the rules of recycling in all the areas my readers live and assume that y'all are grown up enough to KNOW how to properly dispose of things as required". (words to that effect anyway)
I think one honest go at Ebay OR Cash Converters OR Gumtree OR a local textile recycling/reselling shop is a good compromise. The ones that just take your stuff and give you money/store credit are particularly in the spirit of "just send joyless possessions on their way" in my opinion.
We're getting the loft insulation redone and flooring at least some of the space up there so I've run out of excuses to get stuff down from there. And since the workers are coming soon, I HAVE to do that before other types of Konodo. Somehow, despite knowing by the time DD was 6 months old that she was our last and only child, somehow we managed to keep ALL her baby things (including the majority of the clothes 
After going through the lot, I've kept way more than I should have about 1/3 of them for momentos/her children/because I couldn't bear to part with them, boxed half a car boot full 1/3 for the next baby in the family (due at the end of July and his parents are quite chuffed to have the stuff coming), and sorted the other third between a coworker of DH who is having a baby soon and kept a tiny pile to try and sell (like the DKNY baby set someone gave us 
). If I don't manage to, a charity shop will be very glad to have them I'm sure!
This has taken a toll on the tidyness of my living space but will be worth it in the long run (when I don't have to deal with the stuff later, because I've dealt with it sooner)