So these actually work a lot better than my other wool ones when it comes to softness and static. So I'm assuming the silver threads actually work. Static is usually minimal although if I have a lot of cotton based laundry (towels, blankets, etc.), the load does come out a bit static-y. As for drying time, I feel like it is unchanged regardless if I used them or not.
I do like these balls; however, I've had to fix the silver thread on a couple of them already because it was coming off. So I'm not sure on their durability since I've been using them only for a month. Only time will tell, I guess.