Vash watches, with increasing disbelief, as younger him first covers himself with, and then pours, the powdered poison into the worm box. If it's safe to have all over his hands like that then it's not going to do a thing to the worm, he wants to point out, but he's too busy being grossed out by the idea of eating a worm that size. Or any worm, for that matter -- his world sees them as a starvation food, and while things have been rough for awhile, there's still options other than eating bugs!

"No... well, yes. Well. One of them? But not that one in particular, apparently." He's got some toma jerky in one of these pockets, doesn't he? Ah, yes! "And yes, because they also though I was him." He holds out a hand, with a chunk of dried meat wrapped in a scrap of paper. Jerky? "Would you like something to eat that you don't have to poison first?"