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It depends how blunt you let them get. :)
I usually don't go below US grit 600 and that's with very blunt, to me, knives unless I'm changing the angle or grind.

Can't say I've ever had that soup but gelatin in water is thin when it's warm as that's how you usually use it (not that I've ever tried tasting it in hot water alone :) ) to make any sort of jelly....