That's quite an interesting idea; hypothetically it should work to reduce nausea but will it still be absorbed quick enough is the question. I had not heard of these before either..
From doing a little reading one brand stated it's gently released over a period of 3 hours in the small intenstine.
I don't think this is viable for SN as enzymes in your body work to reverse the process of methemoglobinemia so you want it to absorb quicker.
People have used gelatin/cellulose capsules to avoid the taste. This should reduce Nausea slightly in my opinion; so should Cimetidine/Ranitidine as it aids the absorption of SN
From reports I've read, SN in water will achieve unconsciousness the quickest. Capsules seem to have worked smoothly for a few people but can take around an hour to induce unconsciousness