How about finding out if, once frozen wax crayons and chalks will still work ..
Freeze
crayons and
chalk sticks in separate containers and excavate using
squeezy bottles filled with warm water, have some
heavier paper ready to see if the tools still create marks once they've been freed .. extend by exploring other waterproof/water repellant and water absorbing/porous materials
xx
...................~*
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