Has any one ever tried using silicone oil lubricant to stop the brass choke sticking in its enclosure? I am thinking something light would not affect the rubber washer but I am not sure about contact with petrol. Any thoughts?
I have never had a problem with the slider, but a bit of lubrication would never harm.
My problem in the past was with the cables seizing up due to lack of lubrication.
I presumed any oil there would soon wash out. I have sometimes dressed the plungers (I replace them fairly regularly) with a fine grit paper to ensure a nice sliding fit.
Cyclobutch is quite right anything in there will be washed straight into the engine when the choke is used 
CHRIS