Used it many eons ago to germinate and sow parsnips . The specific advice given then (GQA? possibly) was NOT to use the paste which contained a fungicide. It worked and we were thinking of doing it again this year if the parsnips failed to germinate again.
Not so sure about very fine seed, if the depth of paste was too much then, in the length of time it took to dissolve, the seeds may have rotted. Worth giving it a try though.
I put the paste and seeds into a plastic bag and cut off one corner to sow in a drill. (Rather like icing a cake)
Dry fine sand is an old trick used very successfully by many people.