It's citronella that was the key ingredient in original SSS. You can get a version that includes it but I didn't think it worked at all (although midges seem to find me particularly appetising unfortunately...).
I've started using Smidge and it seems to work well, although I double it up with DEET - Smidge going on exposed skin and also using a DEET spray on my hat, buff neck gaiter thing, and on the backs of my gloves. Smidge stops them biting but doesn't repel as strongly as DEET so I find using both keeps them at a distance better. Just Smidge can still leave you miserable in a cloud of the little feckers landing on you and getting in your eyes/nose/ears etc.
I've started using Smidge and it seems to work well, although I double it up with DEET - Smidge going on exposed skin and also using a DEET spray on my hat, buff neck gaiter thing, and on the backs of my gloves. Smidge stops them biting but doesn't repel as strongly as DEET so I find using both keeps them at a distance better. Just Smidge can still leave you miserable in a cloud of the little feckers landing on you and getting in your eyes/nose/ears etc.
Skin so Soft is fine if you are watching an especially tricky episode of Countryfile. There was an older version of it (I think they are now making it again specifically as a midge repellent) which contained an extract of lemon oil (something like that) which some people believe is a mild/moderate repellent for midges but they changed the formula and so more recent versions, except the one specifically marketed as an insect repellent, contain nothing at all that will repel insects. I suspect some people get it to work by applying a layer thick enough such that the midges can't get through or stick to it and drown.
DEET is OK, but melts everything including your car, rifle, fly line, fishing rod...
The active ingredient in Smidge (and some other preparations) was produced by Bayer to repel midges - they did the science and produced the product. Even when the midges are bad it works with the big positive that it doesn't melt anything and, as I understand, even the EPA consider it safe to use on kids. On this basis it would be my recommendation - get something designed to do the job rather than something that might work a bit if you get lucky. The active ingredient has been marketed under a range of names including saltidin, icaridin, bayrepel and picaridin so look for something with one of those in it. The Smidge people claim their unique selling point is that their preparation is waterproof and my experience is that this seems to be true providing common sense is applied. The other advantage with Smidge is that just about every Tesco, fishing shop, post office, ourdoor shop etc. north of Perth sells it
Interestingly I've been out in Ireland on a few calm days recently and have not found the midges at all bad, despite conditions being ideal, but they have been bad in Scotland. Bad is a sort of relative thing though as even a modest attack can make your life a misery.