We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "Mat C" saying
something like:

So, any thoughts on how to get the pipes clean?

Test tube cleaners or similar - you know the type of thing, bristles
twisted on a wire, available in all sorts of flexibility.
If the pipework is too twisty, can you disconnect it and fill it with a
solution of sodium hydroxide /borax / bleach?