Hmmm, sounds a lot like my experience.
If it was me I'd pull that cube apart and wash everything in a mild detergent or soap, let's say baby soap, and warm water, dry everything thoroughly and worst case you might need new $2 stickers.
Or you can panic like I did and trash your cube completely!
(I suppose you could just try to *gently* work it all in and even let it sit for a good while to let some gunk evaporate?) ...
Anyway, I'm also in Oz and couldn't easily source the Silicone I really wanted so I went with the best of Bunnings "3-in-1 Professional Silicone Spray" ...
First time it made my store-bought cubes sing! One was a recently bought cube and the other an original 80's "Rubik's Cube". All great so far.
Months later it was time for a re-lube and then BANG - a totally different experience! My new cube just sort of seized up and massively *increased* in friction!
In a panicked rush I tried to juggle it about and I ended up breaking a center piece, snapped right off the core!
What went wrong?
???
Maybe I didn't shake the can enough?
That 3-in-1 is only 2-4% silicone and the other 96% of gunk is designed to degrease, penetrate metal parts, protect against rust, dry clean, etc etc - it's a far cry from 100% plastic friendly silicone!
Maybe I spayed too much?
Maybe there was a built up of plastic particles and I should've cleaned the cube out first then re-lubed ? ...
Anyway I'll never know that cube is now toast.
I've seen youtubes of people doing "plastic welding" to their cube with Jig-a-loo or so called CRC (they make tons of products, I presume we all mean CRC Heavy Duty Silicone..." - again - all these products are usually designed with rusty metal in mind - not cubes!
Hope it works out.