Throttlebox lubrication

[jimed]

The throttles have been a bit sticky on the S but after some blasting with carb cleaner they seemed fine; however after a few minutes they stiffened up again as if some lubrication was needed. I've given the outside springs. etc. some WD40 which has helped but am wondering if I can put a little silcon spray or similar on the shafts inside the throttles to help. Question is will this attract muck, etc. which may defeat the object so any recommendations/thoughts??
Jim