Etching steel questions

Greetings all you chemical type folks, I would like to know what the penetration really is when welding with the Lincoln SP125 Plus welder. TIG too. I have tested the welds with the mechanical method. I have also sawn through the welds and looked at them. But apparently etching will show not only the weld penetration but also the Heat Affected Zone (HAZ). I'm not sure that when sawing through the weld it's the weld metal I see or the HAZ. The only recipe for steel I've found is made from nitric acid and methanol. Sometimes the nitric acid is called "fuming nitric acid". I already have the "fuming nitric acid", I bought for passivating small prototype stainless steel parts. A little of the stuff goes a long way. Even though I follow ALL the proper precautions when using the stuff, including proper disposal methods, it still makes me nervous to use it. On top of that I'd need to buy a gallon of methanol. I use denatured ethanol (less than 4% methanol) as a solvent for some things since it's much less toxic than MEK and 100% methanol. So, is there another etchant for steel that is less dangerous than the nitric acid/methanol solution? Would ferric chloride work? It doesn't need to be fast, it just needs to be able to show where the weld stops and the parent metal starts, and the HAZ. Thanks, Eric R Snow