[Nabeshin]

I thought this could be circumvented by simply timing the disappearing ink, by for example handing in the parcel at a Friday evening so the ink disappears during the weekend when there is nobody to watch it?

Yes, the timing of the disappearing Ink Is the key to the LIT's success.

My post Is based on the Ink prematurely fading due to a miscalculation on the SE'ers end.

I Is the LIT method based solely dissapering ink , how would this work if I have to use return label Amazon provided me with please sir

You print the label with disappearing ink, you'd need a special printer for that though