the following is edited from some notes i have ref equipment used in BD work ,the notes are from the very early 1990s ,but i believe its referring to the same if not a similar version of the item that has been posted.
BD liquid is used in the immunization of electric capacitor resistance fuzes...
Saline or salt solution as mentioned in the earlier posts in this thread is used to flood the moving parts of mechanical clockwork fuzes as part of their immunization.
Bomb disposal liquid test electronic with battery is listed as part of the stores carried.
use..To test the "conductivity" of BD liquid immerse the electrode of the BD liquid tester in the agent (BD liquid)
a,High conductivity may cause the fuze to function
b,Low conductivity may have little or no effect
c,or safe, conductivity within acceptable limits
when too high or low components of the BD liquid mixture are added to adjust the conductivity until it is correct
The basic components listed for the BD liquid were a a mixture of benzine,methylated spirit,salt and red dye