Silicon injections are clearly the quickest way of making your penis fatter but I would imagine it reduces the hardness of the penis during an erection, right?
It also looks very odd and not as impressive as a normal thick cock with veins, bulging ridges etc. by comparison it looks like a permenantly flaccid "fat" one.
In a year many people that do PE have added an inch or more to their girth through jelqing
, clamping and pumping, although these exercises also have risks, they give you a naturally thick cock with full sensation.
A bit of patience and dedication will give you the cock that you desire at a fraction of the cost.