Sorry my own experience is that it remains pretty solid. Upon that step of combining the Spice solution + FASA you should never evaporate it, but decant it.
When evaporation is done you will cool down your solution meanwhile and drag a lot of water in it, thus you will get a sticky stuff even though your goodies were nicely crystalline when they repcipitated.
But ... I dont think this is relevant here.
So when they are completely dry after removing / decanting the acetone I never heard of them turning into goo.
Maybe convert back and forth again? Would be some work, but maybe you feel better with it when storing.