[casstony]

If there happens to be a piece of grit left on the lens when the lens pen is used, the coatings will get scratched. For this step I prefer to use tightly rolled/twisted Kleenex tissue ripped in half (or other soft, flexible material) with alcohol/water solvent.

I have two lens pens but only use the brush end.

Bintel UHTC cleaning solution is fine though the bottle is quite small. I tend to use isopropyl on eyepieces since most deposits are oil based and water on corrector plates since most of these deposits are water soluble. Occasionally something nasty like sap gets on the corrector and acetone is required.

The key point is to disolve deposits without pressure rather than rub them off.