Tweaks; do they work?

I see all this stuff on the market; spary for CDs, green pens, CD mats, connector enhancer/cleaner, etc.... Does any of this stuff actually lead to a sound improvement, or is it just "monkeyshine"? Please report what has worked for you. Thanks!
Connector cleaner surely makes a sonic difference (I've used Kontak for years, and can recommend it). Upgraded power cords can make a substantial difference. Antivibrational treatments can as well (I use Aurios extensively). The degree of difference no doubt depends on your equipment, and then whether the degree of expense is worth it to you. But none of it is crazy-- everything I've tried has made SOME difference.
Your system probably has to be of high quality to be able to hear improvements of some tweaks, IMO, but some that have worked and become significant to me:
1. Just introduced to Auric Illuminator kit, a variation of the green pen on CD, it blackens CD edges and treats CD surface-- very worthwhile. Optrix CD treatment smooths CD music presentation too, but the Auric kit is quite a bit better.
2. NOS tubes in pre-amp.
3. Hal-O tube dampers (or others) on pre-amp tubes.
4. Seismic Sinks under pre-amp and amp; or other vibration control methods.
5. Good quality outlets, ie Hubbell, FIM, Acme and others.
6. Dedicated AC system.
7. I too agree w/Swklein tweaks. Clean your contacts.
8. Good quality power cords.
9. ASC (or other) room treatment.
Cheers. Craig.
I have a Cary SLI 80 integrated tube amp and a Cary CDP 308 and Paradigm Studio 100 speakers. I use Virtual Dynamics PCs and ICs and Nordost Red Dawn speaker cable. What tweaks would you recommend? I am interested in some of the CD treatment products. What else? Thanks.
I'm concerned about tweaks that stay on a CDs like the green pen or even sprays. Guess it's because of resale value and unforseen long term damage. I do like the AudioPrism CD Blacklight which is a mat that rests on the CD during play, and then you just take it off. You charge it with light and it glows green and helps with static and CD stability. I don't always use it but it has helped every CD I've tried it on. Particularly older CDs with sub-standard fidelity.
Here are a few tweaks for CD that work:
1. Marigo Orpheus Crossbow CD Mat
2. Torumat CDX-16-3 Disc cleaner
3. Endust Anti-Static sprayed on the Marigo Mat
4. CD Stoplight pen
I have tried these and they work. The Marigo is better than the AudioPrism CD Blacklight mat However, I have not tried the Auric Illuminator kit that Garfish recommended. I would probably go with his suggestion. I hope this helps. Happy Listening! John
Post removed 
I've always felt that tweaks are in the ear of the beholder. Except of course for the ones that I've indulged in. :o)
I am sure he meant sparay, not spary. spa-ray is a CD remote control option that turns off your jacuzzi when your CD platter is spinning.
Ok, sprayed is the past tense of spray. One would spray the Endust on the mat, if so inclined. Happy Listening! John
This snake-oil stuff is VERY emptying your wallet. "A fool and his money are quickly parted." Damn, I'd pay someone $1000 to explain that one to me...
The following have worked for me.

Walker Audio Vivid, bettered Auric Illuminator (greater resolution and more energetic sound)

Walker Audio High Definition Links Mk II (lowered distortion, quieter background, improved resolution)

Ganymede VCS Roller Bearings (improved resolution and imaging)

Audiopoint Cones (improved imaging)

Marigo Tuning Dots and Tuning Bands (greater detail,dynamics, and improved imaging)
I have tried bright star products,i had to send them back.
The best investment you can make is to install a dedicated line.
The cost of a dedicated line will vary quite a bit, depending on how much work is involved, but I recently got a quote of $400 for my basement stereo room. It is a rather straightforward run across an acoustic tile drop ceiling.

Of course, when I started asking about the den, where they would have to cut into drywall and run up through the crawl space, the figures got much higher...
of course it depends from the quality.....