Inject the stuff. Once you start getting those super morning erections you know its real. That's how I know my gear is good. Personally I suspend all of my stuf from powders and also Revalor pills so I do not have a problem with getting fake stuff due to making my own. I do have a friend that is on a cycle of known good testosterone and he is not getting boners due to not taking anti-e or hcg. This also affects the boner effect. High estrogen. But no I have never tried to personally tried to crash any gear. That is crazy! Just use it and find out!
I think with something like testosterone, it might be difficult to purposely get it to crash. Worth a try though, couldn't hurt. I'd also get bloods after about six weeks and you should get a fair good idea with your gear is legit. You can also buy OTC a steroid testing kit (google roidtest).