A game mode to practice new champions

Recently I have been struggling with practicing new champions. Bots are too easy and there is always some guy who plays his favourite champion in order to get a million kills. Going straight into pvp is going to be an unpleasant flamming experience and isn't really fair for your team if you are not up to speed on your champion. Creating a smurf account is an option but still isn't ideal as you probably won't be able to afford your champion unless they are on free rotation plus smurf accounts are a horrible mix of noobs doing the wrong thing and arrogant smurfs flaming and not helping.

So my idea is that there could be a game mode in which you are only able to play champions that you have level one or less than 3000 champion points. The mode would work exactly like normal blind pick but only your new champions would be available to you. Obviously you can still get someone with a smurf account playing their favourite champion but the chances would be less as that would only work until he had points. Does anyone else think this is a worthwhile idea?