I too am a chemist. Silicone comes in may forms, but silicone oil, which is my guess of what form of silicone is in these type products, is indeed highly soluble in hexane. The closest thing to hexane you are likely to have around the house or shop would probably be gasoline or kerosene. These have other issues such as flammability and objectionable odor. Lower boiling mineral spirits may also be a substitute.
I have no idea what any of these would do to vinyl or leather, but I know I wouldn't chance it without doing the experiment to prove to me it was OK. How about warm soapy (Dawn) water?
I don't doubt the silicone lubes referred to above are very insoluble, I just don't think that's what is in ArmorAll-type products.
2002 E320 4-Matic
2008 Subaru Outback
2009 Subaru Forester