Thanks for the input here, py...I understand what you're saying regarding the differences between magnetism and "dirty" optical devices and the smoking factor and such (there are no smokers in my household but I understand what you're saying completely and have head that theory before); but as far as these so-called "lens cleaning discs" that are available from just about every manufacturer now, which claim to "brush" or "blow" debris off a lens inside a DVD or CD player, do you not think these devices actually work?
See, with this Allsop disc, there was an area to touch on the disc face before you load it which is supposed to "ground" the cleaner -- I don't understand what this has to do with optical players, as they're suggesting this will "de-static" anything now coming in "contact" with the innards of the mechanisms and yadda yadda yadda...
They
can work if it is only a little dust on the lens that is the problem, but they are not going to be very good at cleaning it if you have something like smoke residue on it. And it is unlikely to ever be a bit of dust that is a problem. Really, taking the cover off and manually cleaning the lens is, by far, the best way to clean it. But, again, if your player has no trouble playing discs (i.e., it actually plays them and does not skip), there is no reason to clean it, and you won't need to do anything for cleaning at all.
Also, if you have discs that skip that are scratched, but unscratched discs play fine, then the problem is with scratches on the discs, not with the lens being dirty. Or if all of your clean, unscratched discs play fine, except for one, then most likely you have a defective disc, which has nothing to do with the lens on your player, and so you don't need to clean your lens.
Since no one in your family smokes, it is unlikely that you will ever need to clean any lens on any CD, DVD, or BD player.
Basically, I would never recommend that anyone buy one of those cleaners that you have, because it is unlikely to ever be of use, because either the lens is not dirty (which is most likely the case), or it will not be effective enough to clean it well enough to make any difference. But there is a small possibility that it might help, so since you already have such a thing, I would stick it in a drawer and try it if your player ever starts skipping. I doubt it will help in such a case, but it is possible that it would. You do not need to use it at all until then.
In fact, it is a bad idea to clean the lens if it is not dirty, because if your cleaning device has dirt on it, it could scratch the lens. Also, the bristles of the brush could get caught on something inside your player and jam something up. Probably, it will not be a problem, but touching lenses that are clean is never going to help, so why take even a small risk with it?
You see, the makers of cleaning products for audio gear are really not in a good business, as it did make sense to clean records and to clean gear that actually made physical contact between the reading part and the thing being played, but that is not the case with an optical device like a CD player. With a CD that is properly handled, it never needs cleaning, and the lens in the player never needs cleaning, except in unusual circumstances, or when people smoke in the same room with it. Of course, they don't want you to believe me, as they want you to keep buying things from them, whether you need them or not. And since they want your money, they are happy to tell you that you need whatever crap they are selling, even when you don't.
If your CDs play without skipping, you do not need to clean either them or the lens in you player. If you get a bit of dirt on one of your discs, it is a good idea to clean it (you can run water on them, and dry them with a clean, soft, lint free cloth, moving the cloth in a straight line along a
radius of the circle, either from the edge inwards, or from the center out, which is the opposite way from how one would clean an old record). If you drop a CD in a mud puddle, that is what you should do with the CD before you play it. But if you don't see any dirt on your CDs, do not clean them. It would be a waste of time and effort and materials.
Basically, they are, at best, misleading in their claims, and, at worst, they are simply lying.
David Hume said:
"We entertain a suspicion concerning any matter of fact, when the witnesses contradict each other; when they are but few, or of a doubtful character; when they have an interest in what they affirm; when they deliver their testimony with hesitation, or on the contrary, with too violent asseverations. There are many other particulars of the same kind, which may diminish or destroy the force of any argument, derived from human testimony."
From
An Enquiry Concerning Human Understanding, Section X "Of Miracles".
In this case, the sellers of the products "have an interest in what they affirm"; i.e., they have something to gain by saying what they are saying. And that, in this case, is why they are saying it, not because it bears any relationship to the truth.
In the future, before you part with your money on audio gear and related products, do research beforehand. For another example, don't get conned into buying expensive wires:
http://www.roger-russell.com/wire/wire.htm