Sorry, but there are no "home remedies" unless you know what you are doing
and you have the parts you will need to replace and the tools to do the job.
If your intention is to mount the regulator an a board and hang it on the
wall, a little brass cleaner will do the trick.  If you want to breath off
of it underwater, have a qualified service technician service it.  To
properly service the regulator a technician will consult with the
manufacturer's maintenance manual for information and diagrams on that
particular regulator.  He will completely disassemble it and clean all the
parts with an ultrasonic cleaner in a slightly acidic detergent bath, then
rinse and dry with compressed air.  Any damaged or worn metal parts and all
rubber parts and o-rings will be replaced with parts from the original
manufacturer.  Most moving parts (but not necessarily all) are then
lubricated with Dow 111 or Crysto-Lube and everything is reassembled.  Most
regulators require special tools to take apart and put together.  All have
critical torque specifications and adjustments.  Once everything is put
together the intermediate pressure is adjusted to the manufacturer's
specifications and then the breathing resistance is measured with a
manometer and adjusted with a special tool.  The regulator is then set aside
and readjusted 24 hours later when the new valve seats have had a chance to
take an impression.

Safe diving,
Cpt. Dale