I am a sceptic re some tweaks , but cheapies sometimes dont cost a lot and perhaps they do help?
I was sent a bottle of some blue cream called Auric something or other as a CD treatment. Works brilliantly on my cds and my spectacles(cleans em well - dunno if it does anything else) and it doesn't harm the CDs. They seem to sound better after a polish with this stuff?
I once was given a demo of a thing called a Bendini clarifier , spins the CD and claims to magnetise or demagnetise or something like that to it , I actually DID hear a difference despite being EXTREMELY sceptical(but didnt buy the unit)

Results of Tweaks are often a psychological thing , IE a result of the listeners expectations Even if in reality they do nothing , in the listeners mind they DO and thus are real to them. Science cannot explain everything , in my country some rural folk die if they believe the local witchdoctor has cast a spell on them!!!!
In terms of listening , our mindsets when doing so are almost as important as the equipment , a glass of wine or a double chiva's or perhaps a toke of something stronger can often vastly improve the system sound smile
Tweaks I indulge in (albeit not all of them are cheap) are:
1) Aftermarket power chords
2) Power conditioners
3) Isolation platforms for my components
4) Aftermarket digital cables
5) Stress relief of CDS (the process of making them induces incredible stress into the plastics and leaving them for an hour at 75degrees C in an oven reduces this big time - I have actually had CDs that have grenaded in CD roms and have cracked from the middle outward in CD player - I work with plastics and this is NOT a nonsense thing - we do the same for a lot of the plastics we fabricate - Be VERY careful if cleaning a CD with a solvent like meths etc - the stress cracks can appear almost instantly near or in contact with any solvent)
6) A decent listening chair
7) Parametric eq
8) Time and freq room correction
9) Pleasant ambient lighting
10) Polishing the pins of my valves
11) Dedicated clean power lines to my hifi


Roon/Tidal, SBT, Trinnov ST2 , Twin Devialet D premiers, Vivid Audio Giya G1 Spirits, dedicated and treated room.
Meridian gear: 568.2mm and DSP5000's acting as TV speakers.