I have just fitted one to my new build, I don't know how well they work but for the sake of about £50 I thought it worth a go.
I have mentioned this on the forum but regarding getting down with your hands to clear stuff, you don't need to do this if you take a mop/brush handle and attach one of those pruning saws that fold out from its handle, attach to the handle with 2 jubilee clips and away you go. Total cost about £12. When you need to clear the bags/rope from your prop saw them off without getting your hands wet, either the stuff falls away or you can hook it out with the saw and toss it onto the tow path or wherever you want
Charles