I'm trying a liquid silicon additive this year. Dyna-gro's Protekt.
Sounds like a similar product, but I don't know anything about that one.
Keep in mind that silicon is a natural mineral. It what sand is made of. Silicone with an E is the synthetic stuff fake boobs are made of.
Do I NEED it? Probably not. Does it help? i hope so, but i can't say for sure. Plenty of plants do just fine without it I'm sure. There is probably plenty in most soils already.
Strong stems and pest resistance sound good to me though, I'm growing an OG strain this year that is known for it's thin brittle stems. Plus it makes a nice wetting agent in my neem oil spray.
I'm hoping it's high PH will also help prevent mold when applied as a foliar spray.
Again I can't say for sure if it helps or not as this is my first time using it, but a lot of people seem to love the stuff.
Yes you can use it in soil, but keep in mind that it has a high PH. Some people use it as their PH up.