I don't know anyone who's had a bad experience with fuel injector cleaner. They're all petroleum based so there shouldn't be any crazy side effects. The most popular seem to be the shell and chevron brands. There are lots of off brands which probably won't hurt your engine but they may not help it all that much either.

You may want to consider using seafoam as well. It can be used to clean the fuel injectors when poured in the gas tank and clean out some of the carbon buildup and crap in the valvetrain and cylinders when sucked up through the throttle body. It's a little rougher on an engine than just fuel injector cleaner. Some have had problems with oxygen sensors and spark plugs getting gummed up. But used right I doubt it would hurt a honda engine with 160K. I've used it on multiple occasions and never had a problem. A lot of guys swear by the stuff. It can do wonders for rough running engines. And being that your engine is pushing 20 years old it would probably help a lot. Search for more info on the board on Seafoam if you're interested.