NO LEAD! Don't ever use lead. Even if Tom was joking, someone might take him seriously. If you have a bunch of lead rattling around, it will tend to wear away and deposit lead onto your clothes. Lead is majorly toxic, causes brain damage, very difficult to get it out of your system. You don't want lead anywhere near you if you can help it, much less in your underwear and socks.
As for the dryer ballz. What Gansky said. They're kinda' cute, remind me of those little rubber hedgehog toys that squeak when you squeeze them.
I imagine the way these work is, as they roll around in the dryer, the little spikes get traction and catch on the fabric and tug on it so it doesn't ball up as much. I'm going to guess they have more of an effect in dryers that only rotate in one direction, and less of an effect in dryers that reverse direction periodically.
Seems to me that dryer sheets have more minuses than pluses; gunking up the sensors ends up costing money for more electricity usage than necessary, and gunking up the lint filter can cause fires, and little splotches can ruin clothes.
I wonder about this: for people who like a bit of perfume on their clothes, is there some kind of device that would hold a water-based scent and let it disperse slowly? Or could a dispenser be installed inline of the air intake or the hot air output before it reaches the drum? Seems to me it wouldn't take much to do the job. Though one might have to be sure the perfumes didn't contain anything flammable.
As for softening: tumble-drying by its nature softens fabrics, by keeping them in motion as they dry. If I take my towels out of the spinner and hang them directly on the line, they will dry stiff and scratchy. But I've found that five minutes in the tumble dryer on air fluff (no heat needed) is enough to soften them up so that when they dry on the line, they come out every bit as soft & fluffy as if I'd dried them full cycle in the tumble dryer. And if you look at the early ads for tumble dryers, 50s and 60s, they always talk about how the drying action itself leaves fabrics soft and fluffy.