That's the whole point of the game!
Dumping resources into walls is an option. But there's a bigger issue here, regardless of whether or not walls are an option. If you're consistently raiding with full storage, then it stands to reason that you'll fill your treasury very quickly. You'll be back to square one in no time. So what are you really accomplishing? You'll still be watching your loot evaporate after you raid and you'll have nowhere to put it then either.
The question is why are you attacking while storages are full? Unless you're trophy pushing I guess. Spend the resources or do FCs to practice war attacks
So let me get this straight... If loot from attacking went into your treasury when a certain storage is full, you wouldn't like it? I'm not fully understanding everybody's argument on why this is a bad idea... So far, the most common message has been to not attack so much. Isn't that what this game is all about?
If you have too much loot, probably your town hall is overdue for upgrading. Too much loot usually means that your attacks are too successful or too easy, for your level. This is easily experienced when playing a low level alternative account, and you invest builder time in non-essential things like defences.
Alternatively, you are a maxed TH11. Congratulations. Yes, SuperCell is at fault, (1) slow to introduce TH12, and (2) at fault cheapening walls. The cheaper walls, combined with greatly reduced troop training times, meant that by doing farming-raids people are able to upgrade all the walls much faster than before.
My argument isn't that it's a bad idea, it's that it's just not a good idea. It's not productive, it doesn't help you. You stated a problem that you have: you raid more quickly than you can spend the loot you raid. Your proposed solution, which is to effectively increase the storage cap, does nothing at all to fix your problem. So why do it?
This is a resource management game. It's your job to appropriately manage your resources, and if you're earning faster than you're spending, then you're at fault for not spending quickly enough. Or for earning too quickly, which you've already said isn't something you want to change. Understandably so. Leave a builder free to dump resources into your walls, or stagger your upgrades so that builders free up more regularly. I don't know your exact situation