Carl Zeiss and others make "lens cleaning cloths" which appear soaked with some alcohol mixture.  I wonder how safe are these tissues? 

 I readily see how pressure when cleaning can be more harmful than any other ingredient.  Grit often is not something dissolvable and will simply move around like a grain of sand unless gently removed before any wiping is done.    On my lens there is UV filter to cover and protect the lens. A filter may be replaced much more economically than a lens should damage happen!

Valou, I likely ruined my first reflector telescope by rubbing the front surface mirrors.

Neat thread of good information!