Depends on the PV but if it's
threaded a soft bristled toothbrush to clean the
threads with some Noalox or petroleum grease to keep them lubed. Microfiber or other soft cloth on the finish of the
device. Contacts vary but removing oxidation is key to maintaining a top functioning PV. You may be able to use alcohol and a qtip to clean them or cape cod cloths, or you may need a worn down fine grit sand paper to remove the oxidation. Noalox on the contacts can help prevent this oxidation in the future.
The MVP has basically nothing but a top connection you can maintain so just keep it clean and you should be fine.