Any time a lens is removed from a camera there is the potential for particulates to settle on the sensor/cover glass. We would recommend caution when considering cleaning the sensor/cover glass as unintended abrasions could cause damage or introduce additional particulates. The following article outlines steps that could be used to clean the sensor of a DSLR: Link. The steps would be similar to our cameras but we would strongly recommend a non-contact method first and a dry method second. If particles remain after these steps contact us before using any solvents or liquids. If you would rather send the camera back to us, we could send you a quote to disassemble it and clean the sensor in our clean room.