Distllled Water

[w3bbo]

Copper sulphate will do the trick which is in effect what PT_nuke is. Bonus is its a neat blue clour rather than yellow iodine. Both do the same though and all you need is a couple of drops max.

 

[Jargy]

Pt_nuke is out of stock everywhere, and iodine is only 85p from Boots, as opposed to little change from a fiver for Pt_nuke. If they essentially do the same thing, and I'm running a closed case (so colour doesn't matter), iodine is probably a better bet in these circumstances, wouldn't you agree?