Use lawn sand instead - should be available at garden centres. Contains weed killers but not food.
Any reason you don't want to feed your lawn? It's usually a good idea at this time of year to get it off to a good start.

One extra point to bear in mind. Moss grows in the lawn because conditions are suitable for it - these are most often a result of poor drainage, compacted soil or heavy shade so the grass doesn't grow as strongly as it should letting the moss get a foothold. If you don't treat the cause of the moss growing, it will keep coming back however much you treat it.