DS made an elaborate curry with rice for dinner last night and then decided to make a cake half an hour ago. He used the same sieve to siift the flour as he had used to drain the rice hours yesterday. Other DS washed up. It turns out he had just ran it under the tap rather than properly cleaning of it. I expect there were bits of rice still stuck to it. Should I let them eat their cake or will it be full of old rice germs?