So after you have tig'd some stainless you are left with discoloured welds and adjoing metal.
The old way was to use pickling paste (a NASTY blend of Nitric and Hydroflouric acids that you really don't want to use. Local welding suppliers now don't stock this due to 'Elf'n'safety - maybe for once they are right)
My local supplier gave me a bottle of pink(!) 50% phosphoric acid (this is called the electrolyte) and a posh brochure for an "Inverter powered cleaning system" from Italy
In a nutshell its an inverter welder set to MMA (no HF sparks please) with a "brush" as the Cathode (-ve) and the workpiece is the anode (+ve) - so earth of the tig goes to work and "brush" goes into the MMA stinger.
So, proof of concept:
Make up a brush out of some s/s bits and and the green pan scourers.
Dip in acid and brush the weld.
Set to 10 amps: not a lot happening
Set to 50 amps: Lots of smoke, pan scourers melting but weld is clean.
Ok, concept works.
Now the pro tools use carbon fibre brushes (at £100 a set of 4 in UK), so some carbon fibre tape has been obtained and brushes will be made.
Note that for Food grade cleaning non acidic, neutral, FG electolytes are used.
Any one ever tried this at home?