that's not Sonax Full Effect gel, unless they recently changed the formula. Back when I tried it (a few years ago) it was milky white thick gel, with average cleaning ability.
I doubt it's the FE version, probably it's just the Sonax Gel Wheel Cleaner or R2000. They're good cleaners anyway, but not FE good
mercedes has a similar product line and the bottling looks exactly like sonax wheel cleaner and the paint cleaner.
since all the companies mentioned are german, it is not hard to precive that the bottles (probably made in germany as well) look the same as sonax. Someone get it and try it out lol