Fairy Platinum are terrible for aftertaste, I've noticed. I think the Finish Quantum tabs I've just bought also have this problem (in that I noticed it on a bowl or spoon I was feeding DD with and I think they had been in the Finish wash - it's possible they had last been done with a Fairy tablet).
Have you noticed this and do you have any tablet recommendations that don't leave this horrible taste on plastic? I worry it might make my children even fussier than they are already...