i bet you use toothpaste every day on your teeth. I bet you even use whitening toothpaste. thats a lot harsher on your teeth then old No. 9 is on your gun.
I've never been a user of harsh chemicals. I use Eezox for everything, that's as harsh as I get. I hear rumors of copper fouling and what-not and I bought some copper cleaner once to get rid of it.... never found any... back to Eezox.
Eezox contains Trichloroethelene so while it might smell fruity it is one of the harsher cleaners out there - TCE being a known carcinogen.
I use Eezox as a rust preventative on some of my older guns since it seems to work so well but I don't use it on everything anymore.
On a side note: OSHA says only certain gloves prevent TCE penetration and that using the wrong ones is worse than going barehanded because the glove prevents evaporation.