You can direct the flavor in any direction you want -- no one says you have to have a hard and fast rule about what goes in.My guess is median whiskey. Also, not sure what the practice is for when to drink from it: drink from it whenever you want or if people wait until the bottle is filled completely.
I started my Scotch bottle from a bottle of Chivas "Century of Malts" -- itself a blend of 100 single malts -- about thirty years ago There's some awfully good stuff in there, and the taste is wonderful.
The practice can become addictive. I also keep separate canisters of a house spice mix and a house herb mix. I used both on a one pound piece of Steelhead Trout tonight, and it was great.
Thinking of starting a general mix of whiskies, rums, Cognacs, etc. Dunno if this is a good idea or intestinal suicide...