Soreness != growth
Hard work in the gym + proper diet + proper rest + proper "supplements" = growth
They don't have these in the yuppie gym that I belong to, but when I lived in Phoenix they used to have an "ice bath" in the sauna/jacuzzi area. After an intense leg workout, I'd go immediately to the ice bath to soak my legs. ( FULL ON TURTLE EFFECT) It did well to help with the soreness.
I used to feel soreness in my legs for around 5 - 6 days. Now it's just a kind of stiffness for a day and a half or so.