I have used electrolysis, molasses, Evaporust, navel jelly and all will do the job if you work within the limitations of the process. Electrolysis is the cheapest but you need a large container for most jobs and you have to be able to put an anode in the solution (I have a 55 gal drum). Molasses as has been said it stinks and draws flies but it does work. Navel jelly works and leaves a phosphoric coat but it is a lot of work. Evaporust works and is reasonable priced but will flash rust and you need to keep it wet. I use a kiddie wading pool and a fountain pump to keep large objects wet.