I gave mine (also Swedish) peas at about 2 days old. I mashed them up by squashing and mushing them between my palms. That was enough to make the peas manageable for them. I used a little dish - about 2 inches across and 1 inch deep and about half full of mushed peas and the rest water. They immediately went into a pea eating frenzy
At the same age (2 days) they got to swim in the bath and they loved diving for mushed peas in there too. You need to dry them with paper towels after and put them back in the warm brooder. They fluff up again pretty quickly. I let them swim for about 10 minutes at a time.