While investigating a reader's question (Yvonne from Germany - your question will be coming up shortly!!), I stumbled upon a very interesting paper. The paper was discussing the use of silicones to help protect bleached hair when it is subsequently dyed (Journal of the Society of Cosmetic Chemists, pg 231-245, 1995).
The type of silicone used
A version of amodimethicone with a high content of nitrogen groups. This silicone type is known as trimethylsilylamodimethicone. It is different from amodimethicone.
The surprise (for me!)
The silicone used penetrated into the bleached hair
-The silicone penetrated because the hair was bleached.
-The silicone's high content of nitrogen allows it to bind to hair
-The silicone was of a small size and therefore could penetrate into the hair
I think the important thing about this is to note that the type of silicone used is not the conventional silicone used in hair AND the hair was bleached (which raises the cuticle to an extent allowing the hair dye, and possibly the silicone in). However, this makes me curious to find out if any other silicones can penetrate into hair.