Entrance
both chests contain keys

Lustlock Labyrinth B1
Secret contains Restoration Scroll

Lustlock Labyrinth B1 pt2
secret contains Fireball Scroll.

Lustlock Labyrinth B2
No secrets, but the spare key from the entrance can bypass the annoyance of the gastrap puzzle.

Lustlock Labyrinth B3
Secret chests contain keys, which unlock the next map and an attack up item (on the top left of this floor).

Lustlock Labyrinth B3 pt 2
Secrets both contain potions.

Lustlock Labyrinth B4
Secret contains fireball scroll