To scour them use a water Jetter as it removed years of build up soap scum and grease deposits and scale.
Concrete and cast Iron pipes are made of cast iron and plastic piping systems normally use plastics
Yes, they can be opened for routine sewer and drain and leader cleaning
Lots of penetrating oil and / or carefully heating with a flame.
I'm not sure, I believe so though.
Rusted cast iron.
cast iron
Welding with cast iron welding rods
4" is the standard house sewer main
galvanized water lines, cast iron drain lines, sometimes lead pipes, terracotta or clay pipes, and in rare cases wooden pipes.
Water mains. Sewer line.
Pvc pipes are cheaper. They are easier to join. They last longer.
bleach might work a little bit better then water but your best solution is get a drain cleaner solution or snake out the line. cola or coca cola has been known to disolve cast iron pipes but I never heard of or tried it to clean pipes.