Lurker1- I use an Allsop carbon edge diagnostic DVD & CD laser lens cleaner on my HI - Fi cd player it seemed to reduce drop outs.
Have not used on DVD/CDRW so can't comment. Has the advantage of cleaning and has set up info for stereo, balance, dolby 5.1 etc so can be used all round the house so to speak.
I have also been warned against the q-tip trick as well lens can easily be miss aligned.
Good luck
Howard