Unusual Etch on a Moro Blade

[Spunjer]

and then this happened...
i was etching this kris as i thought i saw some squiggly lines along the edge. after spending an hour applying vinegar with a stiff nylon toothbrush (my preferred method), i finally started to see some lamination patterns in the usual typographical pattern. vague, but it was there. another hour spent applying vinegar with the toothbrush, but it seemed like this is about as bold as it will get, so i decided to neutralized the acid. after that was done, i ran hot tap water to wash off the baking soda. this is where it got weird. these unusual snake like lamination patterns started appearing all over the blade. the longer i applied hot water, the bolder the patterns got. it even overtook some of the typographical patterns, as in these darker lines were on top of the previous patterns. i've never seen this happen before. anyone ever had this experience? any explanation on what would cause these? one thing that is neat tho, it has this monochromatic scheme going; brass handle and baka-baka, darker brass collar, copper wire handle, and now these brown lines.
p.s.
for the record: i've handled moro blades for years, and i could honestly say that this is the very first time i've been "bitten" by a moro blade. weird.