Okay - I know this may be elementary for those of you that have done it... Just in case there is someone that hasn't thought of this before...
I had to laser something really shiny this morning and when placing it in the laser, I noticed there was a speck of something on the lens in the reflection. Without any effort, I grabbed the cleaning stuff and used the reflection to clean off the lens.
Afterwards, I thought to myself - that was easy to clean with the reflection, actually easier than the normal cleaning. So when done, I put a piece of mirror in there to see if it would work as a cleaning tool and was shocked at how much I missed.
So the next time you need to clean the lens, put a small mirror under there and give it a look...
Steve