"So, you guys are saying that as long as the Hoppes is not left on for an extended period, I'm alright?"
Basically, yes. Some of the newer, more aggressive copper solvents might do some damage over time, but standard good 'ol Hoppe's won't, AS LONG as you don't leave in on the nickel for long periods.
Again, clean the gun and wipe the solvent off.
I have a friend who's a retired Deputy Sheriff. He's carried a old model Colt Trooper in nickel for 30 years. He always cleaned it with Hoppe's, and other than the wear and tear of 30 years of police use, the finish is in fine shape. Since it was his duty gun, he cleaned it, wiped it down, and put it in the holster for the next shift.