The phrase "like a big dug eatin' beetroot" is used to describe an endeavour in which the participant employs the same gusto as a dog would when eating beetroot, ie "look at that burd, I'd be in there like a dug eatin' beetroot".
Imagine, if you will, a snowy white Jack Russell peering into a giant vat of delicious beetroot (you see dogs have a dichotomy, there is nothing dogs like more than the taste of pickled beetroot yet they know if they were to start eating, they could never stop).
A dog would eat beetroot until its wee jaws were positively aching with chewing the sweet, pungent orb of purple goodness. And there is where the quandary lies - a dog would literally gorge itself to death on beetroot if it had a large enough supply, it knows its stomach can't cope with the volume, yet still he wolfs down the delicious Baxter's manna.
Now imagine the wee Jack Russell jumps into the vat, turning his once virginal fur into a sleek violet wetsuit. This is the most amazing sight a man will ever see, watching the sorrow on the dug's face as he realises that no matter how much he can eat, he will never be able to eat enough. Truly spectacular.
