Answer:
I can travel from there to here by disappearing, and here to there by reappearing.
You throw away the outside and cook the inside. Then you eat the outside and throw away the inside. What did you eat?
I am black when I am clean and white when I am dirty?
Walk on the living, they don't even mumble. Walk on the dead, they mutter and grumble.
This is rectangular, hollow and has a lid, and where youβll find it you might wonder, it is just six feet under. What is it?
If itβs information you seek, come and see me. If itβs pairs of letters you need, I have consecutively three. What am I?