'Minor scratch' as mentioned by Binary 007 indeed could be handled with wiping the CD with a wet cloth. I don’t say it’s a sure shot, but may work. I have done it a few times and it does work. Wet cloth helps remove the dust and makes the surface clean and in turn may help the laser to actually read the data as it passes over the minor scratch.
If it works and if CD holds critical data, you may be successful in copying its data to your HDD for burning it later.
In that case spraying a head cleaner solution on cassette player tape head would also qualify as ‘unusual’ because we are applying some wet solution to an electronic device.
Normally a very minor scratch can easily be handled by CD laser, however if it fails to read, CD may keep rotating & Drive light continuously flickering.
One thing I forgot to mention is that there are some good CD data recovery softwares available on download.com. You can try and see if it works with your scratched CD. However most of them are sharewares and hence if successful in recovery may not extract full file unless you purchase/register the same.