rfpd
Personally, I think that experimentation is all part of the game. Experiment, copy your favourite singers, whatever, and get feedback... also, it is ok to challenge the feedback. None of us has all the answers. We only have opinions.
My own opinion is that "copying" your favourite singers/sounds happens naturally anyway, but over a long period of time, and your voice becomes influenced by, rather than a copy of, theirs. I think this happens naturally since the day we are born. So, yes, your unique voice, reflects a lot of influences.
So, you have made the decision that you want to build intensity into your voice for particular songs. And you want some "distortion" in the sound (grunge, gravel, grit). Fine. Don't be surprised if that takes AT LEAST a couple of years to achieve. The FOUNDATION for that can be found by googling or youtubing "singing breath support". It won't teach you about distortion or grunge, but it will lay the foundation for being able to diversify. My advice would be not to be distracted by the grunge sound while you explore "support". Your voice is going to drift in the "grunge" direction anyway, almost without you noticing, simply because it is what you like.
Once you have good support technique, then you will be in a position to actually focus on distortion.
Hardly anybody does the kind of distortion you are aiming for, "naturally". It is an affected sound, much like classical singing is an affected sound, and, when you are ready, you have to actively train it, but not before.
Here is Luciano Pavarotti..