Ok this is how you do it! Tickle him till you can get the fire hose. Click in the game then drag your mouse out of the screen and let go. put it back in the screen without clicking. get him stuck into a corner with the hose constantly spraying him, watch and make sure he doesn't get out. Leave for ten minutes and get a snack. come back and you have 3000.
I beat lvl 50 no prob. Tac shooters upgraded to blades on every corner, 3 fully upgraded spikelaunchers, 2 missle pods, fully upgraded, 1 fully upgraded super monkey, with the tower upgraded making the super monkeys range the whole map lol