What about an aerosol silicone spray Daniel?
Yes, that is also in my lineup, but one must be careful that they don't use solvent carriers and propellants. There is also the issue of getting it where it needs to be and not all over the sides of the model. I typically spray it into a receptacle first, possibly mix in a little graphite, and hope that it will help wick the graphite into the area needing lubrication, so that it has a silicone/graphite double whammy, as it were! The eye of a good sized needle is sometimes used as an applicator for hard to get at spots that have much detail in the way. Graphite does tend to be a bit messy to work with, but on the model it seems to end up looking like scale grime and worked grease, so adds some sort of weathering realism in my eye. Another thing about graphite is that once you get, say an open gear face, well coated it is then lubed for a very long time to come, as it seems to imbed slightly into the plastic.