You set me off on a research mission too....
The word on glyphosate and equisitum is that you need to treat for several years, possibly, and do it frequently, bruising the growth every time you use it, so it may be that it does work eventually, but people who try it aren't persistent enough. At least 4 treatments a year are necessary, maybe up to seven, depending on growth.
There is supposed to be an organic method of controlling it, which involves digging out, (not by mechanical means) as much as humanly possible, then hoeing off an inch below ground the green shoots that reappear when they're no more than 3 inches high. This is said to exhaust the main roots (at least 7 feet down) eventually, and they give up. Labour intensive, not a quick solution. Same theory applies to the 'grassing over' solution - constantly cutting the grass and the equisitum is said to weaken it over years till it gives up and dies back.
Or there's Kurtail (previously Kibosh), which isn't technically available to gardeners, is for professional use only, but seems to be freely available on E Bay. This product, though, is the one responsible for contaminated horse manure, but so long as horses aren't grazing, or the resulting manure used before at least 3 years of composting has passed, it shouldn't be an issue. It's a contact herbicide, so careful use amongst other planting is necessary, as with glyphosate, but repeated applications are also required, though it is more effective than glyphosate.