Best solution to soak metal parts in.

In my rebuilding of lots of brake and suspension parts, i use Superclean, to get the parts squeaky clean, then use a 5 gallon pail of Evaporust that i buy, to get rid of the rust.
Those are very good products.
My 2 cents to answer your question.

X2
Hemi71x recommended these to me last year and they worked great.