Wow! I'm new to this board ...and I just read this whole thread. You people are incredible. You're all over the map on these issues. Guess I'll weigh in with my vote. Leave only footprints. Flagging tape is not footprints.
As for TP, practice the ancient zen art of wad fluffing. Wipe, invert your wad, and allow gravity to deconstruct your wad into a state of fluffiness. Carefully pile your fluffed wad, with the soiled part on top (it's tricky) on some bare ground or rock. Torch it.
Remind me to share a story about dumping toilet vaults in Boston Basin some time ...especially the part about why my partner shaved off his mustache. Yuk!
