Some basic notes on cleaning -
1. When thinking about cleaning the vulnerable optics of a telescope, usually the first element that is open to the light,
DO NOT LOOK AT THE GLASS WITH A TORCH !
This is almost guaranteed to convince you it needs cleaning.
Instead rely on your experience of past occasions of looking through it.
2. If in doubt -- DON'T ! DON'T ! DON'T !
3. Try your best to avoid moisture getting on it, this will allow dust to stick to it making it more difficult to clean without damaging the coatings.