Never tried it, I might get some pay day and experiment with it.Its all pretty pricey. Occasionally some bargain stores like Crazy Clarks or The Reject Shop, have some cheap brands on sale, but its not much cheaper than what you get at Bunnings.
Have you tried 2 part Wood putty instead of Autofiller? From memory it was a little cheaper, for the same stuff.
Plastibond my friend
get it from Bunnings, although it aint cheap, about 40 bucks for a small tub of it.