Found an exploit!
If you just click at the bottom of the screen across the length repeatably, it seems like the waste barely makes it onto the screen before its carried off.
I got a score of 3800 and lvl26 using this. I can agree with the others that left clicking on repeat gets tiresome fast.
Also side note, the first time i tried it, i was clicking the bubbles in the background thinking that what i was meant to do, I'd take them out.
Good luck with your game mate! :)