Isuzu Trooper Piston Cleaner

hello all, I have a 94 isuzu trooper. My truck has been idling kind of rough so i recently bought this fluid your supposed to dump into the crankcase. Now this stuff is supposed to clean your pistons and seals and all that to get the gunk and what not out, also supposed to idle smoother and get better gas mileage and blah blah blah. Now at first this sounded like a good idea, i mean what could be bad. However I was speaking to a few driends and 4/5 of they were saying dont put it in, it could be bad, by cleaning your seals on an older vehicle could actually clean it too much and cause a leak. So im holding off on that I just wanted to get some other opinions if this kind of stuff is worth putting in, or if I should just hold out and get my truck tuned professionaly rather than just dumping "cleaners" into my engine. any thoughts on this?