I almost tried using mine for that this winter, but decided I didn't want to risk salt residue mixing with grass seed. If you use it for both I'd clean it out really well or maybe get one for each application.
You can't determine that with a handheld spreader because there's no feedback for how fast you walk. With a wheeled broadcaster they can tie it into the wheel RPM and provide more exact coverage numbers.
Too bad that 'sunday' brand seed is.......we'll i'll say, 'not very good at all' good luck with the inert matter and weed seeds you just spread everywhere.
I've used mine for two seasons now, never had the chute clog a single time. Although I have seen quite a few Home Depot reviews claiming it clogs up easily. I've only used grass seed in mine, usually on setting 3. Were you spreading grass seed or something else?
Clean it in hot water opening and closing shoot. Obviously take battery out and then blow out with air compressor. Have been doing it to mine daily use it multiple hours a day for a few months now.