Quinoline (Chinoline in German), Monochloronapthaline and Monobromonapthalene are all quite nasty. I would avoid them at all costs. The other mixtures or chemicals such as tetrachloro ehtylene and the Toluol are not much better and the Toluol is quite flammable. The latter two are volatile.

No, you need a non-volatile liquid that does not absorb moisture. Nose oil, glycerine and silicone oils will fill those requirements and are also relative to the ones mentioned above, non-toxic.

PE