Line Conditioner

Are line conditioners such as 'Real Magic' effective or are they just 'smoke' in a bottle?

I must confess being skeptical when I started working at BPS and was told "we spray this (Real Magic) on all monofilament we spool on reels" that it was 'propaganda'.
Well it does help IMHO and certainly doesn't seem to hurt the line or the reel or rod.
It increases mono line life expectancy, reduces line twist and dryness, and seems to reduce the onset of corrosion to guides and reel parts when applied regularly after use.

Yes, I drink the kool-aid ;-)

Here's a link to great discussion on the topic from about 5 years ago.
Not 100% positive consensus, but they look like genuine responses...
Line Conditioner...Pro or Con - BassFishin.Com Forums

Pass the Kool-Aid. I use it on some really cheap freshwater spinning reels that I bring down 3 or 4 weeks a year and have even submerged them in saltwater while surf fishing. I did have to take one apart (Diawa 3500 $19.99 at J&M) and clean some sand and grit out but it and the others are all still in good health. IMHO the key is applying it and letting it dry BEFORE exposing them to saltwater. Clean with cool clean freshwater afterwards, let dry and reapply Real-Magic. Someone correct me if I'm wrong but I think it penetrates the pores of mono and prevents it from absorbing water, making it last longer. Either way it is a cheap way to make your equipment last longer.