the coils in the tuner should not be touched, you can alter the tuning by collapsing or expanding them. Hopefully you did not change the shapes of the coils. No need to clean the tuner unless its noisy (snowy picture). When cleaning only the contacts need to be cleaned. Spraying is bad as it can get into places it should not be. Best bet is to leave it be for a few days and IF spray got somewhere it should not be it will dry out.
IF the fine tuning ring has no effect then there is prob something wrong with the mechanicals of it. fine tuning def effects the picture, generally it goes from black and white smeary to beat freq sound bars to loss of sync. see my video re fine tuning about how it should look.
https://www.youtube.com/watch?v=RAk9lKv03zA
Note your 7 may not have the range as demo above but you should still have a range that shows change.