Why don't you like the cold processes? The copper oxide process works well if the metal is clean, and provides a nice black finish, it was often used for pliers etc...
The Hydroxide process you seem to know about, it is nasty, clouds of hydroxide vapor are not pleasant, nor are they healthy. Be aware that sodium hydroxide vapor can cause instant, permanant blindness if you get it in your eyes!) It's main benefit was that it was cheap, not that the finish was particularly good, parkerizing is a much better process.
fwiw, some of the chemicals in the typical recipies for that process aren't really necessary, they are in there for production cleaning the metal, deoxidizing it etc, if you start with carefully cleaned metal, you don't need them (typically chlorides)
There is a black lead process, it is also nasty, and very toxic. (I think this was more common on sheet than tools tho)
You can also use oil quenching to produce a semi dark finish, but you need to heat the metal quite hot, the smiths sometimes do this...
