Clean only the accessible seal surfaces using the method in the appliance instructions. Do not pull the gasket out of its mounting or use sharp tools to reach into its folds.
What the observation tells you
Food debris can prevent clean contact, but aggressive scraping may tear the flexible material. Oils, solvents and strong chemicals may also be unsuitable. Cleaning should reveal the condition of the seal, not stretch it into a different shape in an attempt to improve closure.
A useful next step
Wipe gently, dry as directed and check that loose packaging is not trapped when the door closes. If a section is split, detached or permanently distorted, record its position. A model-matched repair assessment is more useful than applying an improvised dressing.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.