You need to buy this can of contact cleaner. (This brand is the cheapest. CRC brand is the most expensive) But both work the same.

What these do is clean the metal off those corrosive battery acid. First get a piece of rag ready. Try not to get the liquid on to the rubber button areas. Contact cleaner is not rubber friendly and will remove those lettering or even melt some rubber. So be careful in this aspect.
So it is better you try to spray in a position that allows the liquid top flow away from the remote buttons.
Remove the remote cover and spray on to the corroded area. Do it in small burst. Then wipe and scrub with fingers in rag to remove rust. Do a few times until satisfactory. Use Q tip cotton buds to clean hard to reach areas. You can spray some on the bud and scrub it.
It dries in seconds. But if you are afraid that some liquid might pool inside the remote, you can just allow it to dry for 5 minutes or more.
Now you have stopped almost 99% of the metal corrosion in the battery contacts. I have used this product on torch lights, clocks & calculator with good results. Though every one of them are cleaned in a different way. But the results are the same.
This post has been edited by netmatrix: Aug 27 2017, 02:35 AM