The use of things like white grease and silicone "dielectric" grease on electrical contacts can be detrimental in the long term. Organic materials like white grease are made by oils lithium soaps and materials like bentonite clay. When exposed to arcing the oil breaks down to carbon and results in what is called coking of the contacts. Kluber the lubricant company says the following regarding switch contact lubrication "For lubricant selection, it is also of major importance to consider what kind of metal surfaces are moved against one another with what contact force. The adhesion of the lubricant depends on its chemical composition and consistency, but also on the contact material, the surface roughness and the orientation of the roughness. As lubricants applied to live electrical contacts must withstand very high temperatures over a very long period of time, the base oils should show a very low tendency to evaporate and a high resistance to oxidation. If temperatures become excessively high for a short time, the lubricant should evaporate or burn away without residues such that no foreign matter (coking) remains, which would interfere with the function of the contact later. When faced with requirements of this kind, perfluorinated polyethers (PFPE) perform much better than hydrocarbon-based lubricants."
Electrolube has the following comment about silicone compounds "Silicone Contamination Silicone contamination poses particular problems which can also be overcome by contact lubricants. Silicones are found in lubricants, sealants, polishes and mould release agents. As silicones can "creep" great distances, these products should not be used in switch assembly areas. When silicones are present between moving or vibrating contacts, they react under arcing conditions to form silicon carbide. These crystals abrade the contact surface and cause electrical breakdown. Silicone contamination is very difficult to remove, particularly after the formation of silicon carbide. It cannot be removed by solvents. There are certain contact lubricants that can prevent the damage caused by silicones and can even restore damaged contacts. One such treatment from Electrolube reacts with the silicon carbide to form volatile silicon tetrafluoride gas, thus slowly breaking down the hard particles.
If a contact lubricant is used on the switch prior to the introduction of silicones these problems are avoided." so as they say "you pays your money and takes your choices" with regard to what one put on our switchgear. The concern I have is the main ignition switch is pretty fundamental to the bikes continued running and I would be nervous of anything which could degrade the performance of the switch in case it decided to stop working just as I was overtaking a big truck. Silicone spray is great for water resistant spark plug caps to stop the rubber sticking to the porcelain of the spark plug and to help deter water from entering but that's about all I would use it for on the bike. The other thing about silicone greases is they migrate over surfaces and a very challenging to remove if you want to repaint. The bottom line is we all use what we are comfortable with and can afford/get hold of, it is no good knowing that a particular substance is the "ne plus ultra" lubricant or whatever if it is not available within a thousand miles of where one lives, one of our fellow listers in Aus is faced with that on a regular basis as he is physically remote from lots of special bits and pieces we rave on about but that is balanced I am sure by the magnificence of the location.
Regards,
K-BIKE