Best way to clean my old CD’s

Just my two cents (that aren’t made anymore)

I think there are two questions here:  cleaning dusty or soiled discs that are other in good condition.  I agree that an isopropyl alcohol solution is good for this. 
The other issue could be some scratches on the non-label side of the disc that affect its playing (might skip or the player might reject playing it).  Years ago, someone on a forum suggested something they have used — plain white toothpaste with no granules in it.  Toothpaste has mild abrasives that might help relieve mild scratches (deep scratches aren’t remedied).  I have used this on old scratched CDs with success.

I have not used this, but another person spoke of a product that can fill in deeper scratches, maybe like an acrylic spray?, headlight spray?, and helped salvage an otherwise unplayable disc.  🤷‍♂️   I can’t say if that works, but if the CD is ruined, what do you have to lose?  

Well I use 70% alcohol its cheaper than 91%..i used little on a ball of cotton ,wipe it on and let it dry naturally or use a fiber drying cloth.The end.

I have found that scratches and divots in CDs disappear with applying isopropyl and strongly wiping with a microfiber cloth.  I suppose if someone really purposely tried to damage a CD with a knife or scissors that might not do it, but we are discussing every day use here

Agree with those regarding not touching your CD's unless you have to.  I handle them carefully and always keep the media side down.  Most of the used CD's I have purchased have been in great shape so I also leave them alone.  If I have to clean I use a light mist of Windex on a microfiber cloth, drawing across the CD perpendicular to the groove direction.