All the PikePro oils i use lose their smell from one winter to the next once opened, the fishyness is gone and it has that old paintbrush smell. Same thing happened with a bottle of hemp oil i bought, i'm sure it had been opened previously in the shop because it had the paintbrush smell too. Smelt nothing like the supermarket hemp oil.
On the other hand i have some sonubaits spicy sausage and luncheon meat goo type stuff, had them a couple years and still smell the same. Same goes for bottles of Korda Goo i have.
I don't imagine it would hurt to put them in the fridge once opened, just let them get back to room temperature before trying to squeeze them out the bottle