It's generally appreciated that dirty contacts can cause intermittent sound or crackles, but even before things get to that dire stage there can be subtle degradations in sound caused by slightly corroded electrical contacts.
Caig has long been a trusted name in contact treatment and we wouldn't be without a can of DeoxIT D5 spray, which has served on all kinds of contacts from audio to bicycle lights.
This kit includes the product in both aerosol and dropper-tube version, plus DeoxIT Gold and DeoxIT FaderLube, both similarly packaged. FaderLube is for the insides of volume controls etc. and may require some dismantling to be useful, so it's less applicable for most home audiophiles, but the others are a great boon.
Various applicators as provided, as well as polishing-off cloths and even some pre-moistened wipes, which are easily replaced by a bit of kitchen towel and a brief burst of spray.
One criticism is that the instructions don't make it entirely clear what's best for what, but basically DeoxIT removes corrosion, while DeoxIT Gold protects against further contamination.
Mini-jack plugs seem particularly prone to failure due to contamination and many a time DeoxIT has got connections to portable audio kit reestablished. It's not strictly cost-effective, compared with full-size cans, but this kit will last for years.
Follow TechRadar Reviews on Twitter: http://twitter.com/techradarreview