Once on, Smoove stays on until you choose to remove it in a bath of chain cleaner. When you so, a great deal of dirt comes off with it. For this reason, I do this every dozen rides or so.
Yeah, I read similar comments in reviews which put me right off Smoove, if I want something dirty sticking to my chain that needs cleaned periodically then I’ll just stick to a thin smear of wet lube every so often, Finish Line green was always my go-to, although am trying some Morgan’s Blue Syn Lube at the moment (works well but seems dirtier than the Finish Line).
Squirt on the summer road bike, it’s one of the many little joys of having a summer road bike that you can look down and see a gleaming silver chain glinting back at you, whilst still enjoying a smooth drivetrain. I’ve never paid much attention to the durability, usually assume one or two long rides before re-applying. When it’s rained I’ve still managed to complete long rides without any drivetrain distress, and as a bonus just need to rinse the chain, let it dry and re-apply.
Using it on a bike-packing trip was a mistake though, it doesn’t set properly inside cold damp bothies!