For the love of everything good and right, don't clean your freaking coins. I don't care if you think they're junk, if you don't know a lot about the series,
you don't know that. They could be a rare date (or a rare variety of a common date), and you just don't know. Even if it's your junk now, it might be somebody else's gem in 50 years time. They don't always go to be melted - a lot of bullion dealers buy and sell bags of "junk" silver instead of just sending them to the refinery. A lot of coin collectors are able to pick out good stuff from those "junk" lots.
Just as an example,
here's a guy who found a dateless 1916 standing liberty quarter in a lot of "junk" silver. Even worn almost flat, without a date, that coin is worth $1500.
I can't tell you how many coins I've bought off eBay, only to have to return them because some idiot at some point in time decided they'd look better polished up. It's not always possible to tell from photos. I had to send back a 1926-S Merc that some idiot must have cleaned with a Brillo pad. In original condition it's a $200+ coin, but cleaned it's worth a fraction of that. I had to send back a cleaned 1924-D just this morning. A lot of these coins aren't just valuable, they're really hard to find. I'm sick of paying return postage so stop cleaning your coins!
It's one thing to GENTLY rinse off loose dirt, gunk or grease, but never rub or polish a coin or try to remove tarnish. 100% pure acetone (NOT nail polish remover) is safe for this purpose, but be aware of how it must be handled and what it does to plastics and rubber. If in doubt, don't touch it!
The same goes for anything old. Ever watch Antique's Roadshow? Some lady comes in with an old piece of American furniture and says "Oh, it was so dark and grimy, so I took some turpentine and cleaned it up nice!" Then the expert bludgeons her to death with an ottoman for having turned a half million dollar armoire into a stack of worthless firewood.