Beware of mutton dressed as lamb in selecting speaker wire. Most electronic wire is already made to be almost oxygen free, and ETP (Electrolytic-Tough-Pitch) is identical in conductivity to OF. Only a very expensive type of OF cable where the silver impurities have been removed has 1% better conductivity. This is only useful in installations with very long cable runs of hundreds of feet like nuclear facilities. In a home theater with a 50-odd foot run at the most from the amp terminals to the speakers there will be no difference in the sound.
If your connections are the simple type where a spring is pressed and a stripped wire is inserted in a hole you should use a tinned wire. The tin will protect the copper from corrosion. Use of crimped spade lugs provides the best gas tight connection of bare copper conductors. Banana plugs that are crimped or soldered also provide a gas tight termination, but the plug interface is not as robust as a spade lug under a screw terminal. Gold plated banana plugs and 5 way binding posts are better, however, the gold on cheaply produced parts will wear out quickly from fretting caused by micromotions in any sliding contact connector.
Your silver wire is most likely tin plated copper. You will be fine.
