I use it for some browning and spotting issues and spotting formulations such as a rust remover that’s gentler on some types of textiles
than Ammonium bifloride
We carry it. Removes mild rust more safely than stronger acids, and is effective in lessening some yellow stains (ie bht) that require long dwell times.
I use it primarily in commercial enviorments where water has leaked creating browning. Around a lot of water coolers I have found to be problem areas and this takes care of it usually.