I have worry dolls too, but they are in some little container of their own, generally speaking you assign the doll your worry and put them back in the container to do the work. I think they can be reused and reused.
I wanted to comment on your original post, I have a ton of little spells like the one you spoke of, nearly all of them are made with biodegradable stuff, so some get hung in a tree, some get buried in the ground, some get burned, some go downstream, some are placed in various areas in the house, but for everything else, I have a ceramic cauldron I made in my college ceramic course, and I place them in there to do the work. Some of spells are really long term, so this houses them well. I have never decommissioned a stone to do other work. If a stone is to be used I will choose one that I am ok with leaving in the spell, but grounding items is the best way to let their energy run back into the earth,
( a moon cycle is a good length of time) then you can re-program them.
Your title says tools, which makes me think of think of things like the cup, blade, pentacle etc...those Items should be grounded like I described above if you wish to let them go. Then gift them to a friend, give to Good-Will, or
throw them away.