What do you mean by 'side chaining'? -Do you mean 'ducking'? If so, can we use a better terminology, since this isn't a side-chain processing application, it's simply feeding a different signal into the detector input, which you can usually cheat by using the side chain return. -This is different to "side-chaining" to me, which is the process whereby a processing device or 'chain', 'alongside' the signal path.
"M.E." to me means 'Mastering Engineer'. -Is this what you meant though, because I don't understand how an ME could really do anything of the sort unless he has stems, and then he's really mixing and not mastering...
Also, do bear in mind that many 'character' analog compressors do NOT have separate detector inputs, the LA-2a and Fairchild being excellent examples.
Plus (assuming that I'm correctly interpreting what you're doing), there are limits to how well it can work: For example, a vocal which varies a lot in level can b used to duck a pad which is getting in the way, but it's far from a perfect application, because when the vocal wakes up and gets going, that may be when the pad doesn't necessarily NEED to be ducked as much as when it's whispering and getting lost behind the conflicting sound bed... whereas it does precisely the reverse.
So such a practice can be fun and produce interesting and quite useful results, it's so far from universally useful that I sincerely doubt that many people use it as a 'primary' tool.
I could be wrong though: -I often am.
Keith