My first-floor toilet is blocked, as far as I can see
just after the U-bend.

My local plumbers merchant gave me a jar of sodium hydroxide,
and told me this was as good as anything.
The label on the container warns me to follow the instructions carefully,
but unfortunately the instructions are missing.
Can I safely pour some down the toilet?
Do I have to ensure it will get round the U-bend?

Any advice or suggestions gratefully received.

--
Timothy Murphy
e-mail (80k only): tim /at/ birdsnest.maths.tcd.ie
tel: +353-86-2336090, +353-1-2842366
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland