Never new of oil based suspension. Cleary I am speaking ignorantly on the subject.
I always thought that because the "water based" suspension left a crystal within the muscle it was injected into, that gave you the local growth due to that muscle having to break it down...
There's some apparent confusion on my end.
Well you are certainly correct that test suspension can crystalize in the muscle. This is what happens when the hormone comes out of solution and deposits itself in the muscle tissue. And yes you are also correct in that the muscle has to break it down. This is happens relatively easy with test suspension - the water the test molecule is suspended in is quick to leave the hormone solution, however the hormone is not. This is why many users complain of severe discomfort when injecting it.
On the other hand, disolving the same exact hormone (testosterone base) in an oil solution instead will help the hormone be released slower (since the oil is much slower to be absorbed than water), which in turn helps with the pain aspect.
But anyways local growth is simply a matter of the hormone itself, not necessarily the carrier in which it is dissolved. Testosterone with no ester (which is what is used in both test suspension and my above mention of "TNE") does not need to be carried into the bloodstream for it to be active. Test propionate, for example, needs to be sent into the bloodstream where our body can cleave off the ester (propionate), leaving the parent hormone (testosterone) behind for it to exert its anabolic effects.
In other words, a hormone with an ester attached to it is not active until released into the bloodstream, where it is then carried to various tissues for it to exert its effect. A hormone with no ester is thought to be active immediately, which provides the rationale behind the theory of localized growth. Since the muscle you are injecting to will have the highest concentration of this ester-free "parent" hormone, it is thought the anabolic effects will be greatest in that area.
Test in an oil based solution is thought to "stick around" in the injected muscle for longer than test suspension in water, which in my opinion, would give it a greater chance of causing any local growth.