I've used Evapo-rust on tanks, tools, and various parts, and been VERY happy with it. It doesn't stink, it's safe on your hands, and won't harm paint, rubber, or the base metal. When it's used up (turns black) it's not a hazardous substance -- you can dump it down the drain or put it on your flowers if you happen to have iron-poor soil.
Naval jelly and most other rust removers are based on acids (usually phosphoric acid) -- they'll damage the metal as well as removing the rust, and they are hazardous substances.
Evapo-rust is not acid-based (dunno how it works, actually) and it's safe to leave parts in it for months -- it only eats rust, not anything else.
The only downside is cost -- at around $25/gallon, the stuff ain't cheap.
2002 Suzuki DL1000 V-Strom, Dark Metallic Space Blue
1983 Suzuki GS850G, Cosmic Blue
2005 KLR685, Aztec Red - Turd II.2, the ReReTurdening