I've not used it myself, but found that some high ranking members over at www.thehomebrewforum.co.uk use it. They say they got it at the Pharmacist at ASDA for about £4.50 for a 500ml bottle. This is then diluted to 2.5ml in 2000ml water, so it's going to last a while!
1.25ml/l is the usual concentration. 2.5ml/l is the maximum no-rinse concentration.
brewuk.co.uk has this advice:
I switched to videne many brews ago, using 1.25-1.5ml per litre of
water to get a no-rinse solution.
How do I use it?
I use 500ml in a spray bottle to brew ( Great for spraying up taps, into tubes and bottles, for other things like FV’s I
pour a small amount into it and rotate the FV, then a quick spray and
make sure everything is properly cleaned & rinsed with hot water
0.75ml per half a litre and also add a 0.5 teaspoon (2.5gms) of citric acid to increases and prolongs its effectiveness. Best use
filtered/treated/bottle water as chlorine and water hardness can
effect how long the solution lasts.
You can get citric acid from BrewUK, it looks a bit like table sugar,
but it tastes foul if used in tea (trust me on that one I’ve made the
The solution is the colour of cold tea. Over time as it loses its
sterilizing potency as it looses its sterilizing effect it loses its
colour. Also best stored out of light!