Chewing tobacco has trace amounts of fiberglass in the product so that the nicotine and other chemicals can enter the body's system more efficiently.
I have never heard this and I have tried to verify this and can't find any relevant information other than quotes that it amounts to an urban rumor. Since many people who have worked with fiberglass develop cancer it just doesn't sound plausible. But if you can direct me to solid info it would be appreciated.

Finally, to the original poster, putting hash oil in your chew might not work unless the oil is a tincture that contains available THC that needs no heat to be activated. (Not TOO knowledgeable in the ways of oils...)
Again what is activated THC?
I get a very nice buzz eating raw weed but I do not understand your concept of activating it.
Could you please elaborate?