"Les Desser" wrote

Just a word of thanks for the advice to run a length of string down the
inside.

Did that yesterday with 1/4" nylon rope and it seems to have solved the
problem!

Pleased to hear it Les.
Just a word of warning (my Mrs is constantly nagging me about the fact that
I see all the likely practical issues rather than the glitsy end result!)
this is likely to form a trap/collection point for leaves and debris.
Make sure this is your first stop when cleaning the gutters!

Phil