Corrosion/etching at the liquid air interface is common in industrial processes. I don't know much about Kaboom, but if it is generating some free HCl in solution then over time I wouldn't be surprised by some etching of the interface--the waterline.
In one of the processes I worked with there was dilute HCl and acetic acid along with organics (some of them chlorinated which decomposed into HCl containing polymer) in the distillation train. Granted, this was boiling water, not room temp. Over the years the ceramic packing in the first distillation tower would have it's aluminum and other minerals leached away. Eventually this would result in some ceramic support failures for the bed. When I shut the column down to repack it the old ceramic was so soft in places that I carved it away with a pocket knife like damp clay.