Do what I have done. Everytime you need to dump elixir, buy two level 8 walls (1M) and dump your elixir in there.
I now have 12 level 9 walls in the middle of my 238 level 7 walls
The whole "max everything" wasn't meant like that when the game started.
And be happy you can get elixir easy. When you will have 8M lab upgrade to do, you will be happy.
Level 155, TH 10. Quebec Land