Coffee Chaff

[TISH]

Someone recently gave me a garbage bag full of coffee bean chaff (comes off the beans during roasting I think). I am not sure what to do with it. Internet search came up with the info that it is a good mulch but doesn't let water through - so not exactly sure what plants that would benefit...

Anyone have any experience with it?

[aquilegia]

does it smell like coffee? I'm not sure too much about the chaff, but I know you can use coffee grounds to form a ring around plants to keep slugs off them. Might be worth a try?