I stained this benchtop I bought from IKEA with poly and this is the result, I'm fairly sure the "wet spots" are glue they used to fill in any depressions or inconsistencies.
Custom Kitchen Ceramic Benchtops - IKEA
MÖLLEKULLA Worktop, oak, veneer, 186x3.8 cm - IKEA
Custom Kitchen Ceramic Benchtops - IKEA
KARLBY countertop, oak/veneer, 74x11/2" - IKEA
A Sydney blogger's light-filled and lovely IKEA kitchen - The Interiors Addict