richie00boy said:I . NaoH on it's own seems to leave a film behind. ... The stuff I use is drain cleaner.
We eat here that NaOH-cod alsoAuroraB said:If it is sold as "drain cleaner", it might have some other additives...
Over here we buy it at the paint shop as "caustic soda",- also used for paint stripping and heavy duty cleaning
( and beleive i t or not: to make "lutefisk"-- dried cod soaked in lye, then rinsed for a couple of days in water.... a well known norwegian delicacy, mostly used around x-mas time.... and-- it is no joke !!!!!)