Aphid control with pheromones?

Does anyone have experience with pheromone-based aphid repellents? A quick search identified the two products linked below.

http://www.jacksonandperkins.com/gardening/PD/34904/

http://www.amazon.com/Springstar-Aphid-Chaser/dp/B0002J6E5O

Does either one work? Are these kinds of repellents worth using at all?

I tried them in my greenhouse last winter/early spring since I tend to have a lot of trouble with aphids on my hibiscus and I didn't have any aphids. But of course I have no way of knowing whether I would have had aphids otherwise. And the lack of aphids extended well beyond the useful life of the pheromones, and I didn't have trouble with aphids in other areas of the yard that were way far away from the aphid chasers, so I think it's just that the mealybugs and the scale had decided it was their year to feast on my garden and the aphids hung out somewhere else, nothing to do with the pheromones. So I can't say conclusively one way or the other about whether they work or not, but they're cheap and they certainly can't hurt so it's worth trying.

Aphids bite the dust with any acceptable summer horticulture oil spray. Even a soapy spray will "ground" them. I do not think to much of the repellents but I do not deal in greenhouse tech management.