I picked it (iPhone 6) up and the melted slush was in the charging port. I let it dry in home and when I could see no sign of wetness, I tried to charge it but it charges for a bit and then doesn't charge, then charges for bit, then doesn't charge.
Was it "pure" melted snow?
Or was it snow mixed with ice-melt?
And if was dropped into ice-melt, do you know whether it was Sodium Chloride (NaCl), Calcium Chloride (CaCl2), or something else?
If it was dropped into pure snow, you might be fine. A small amount of water, without much dissolved in it,
might not be that bad if it's dried quick. Absent putting it into rice or silicone beads, cleaning it out with a small amount of isopropyl alcohol might help accelerate the evaporation process.
If it was dropped into snow melt with sodium chloride or calcium chloride, you're boned. It's basically salt water, probably the worst option. High high chance any metal it touched is corroded, and even if the water evaporated, the dry salt residue will continue corroding.