What is the ruling on eating bread kneaded in a machine that previously kneaded — without being washed — sweets containing alcohol?

In such matters, one relies on a trustworthy and reliable person. If the worker is not known for their uprightness, then their report should not be depended upon. If what was mentioned is confirmed, then the basic principle for things is permissibility. It appears that theprocess of making sweets removes the traces of alcohol from the machine, and whatever might remain is negligible. The process of baking bread consumes any remaining traces, so there is no harm in consuming it.