I use the block bee's wax. (I also got mine from Bunnings)
I just use a paddle-pop stick to scrape a bit directly off the block near the hole and then use the same stick to pack it in.
There will be a small bit of wax that smears around the hole, but it doesn't matter. It will come off once you start wet sanding, or if it really worries you, it can be cleaned off quickly with a rag dampened with naptha before sanding.

FWIW, I've had that block for about 5 years and it will probably be here when I'm gone. And that's with uses varying from hole plugging to waxing screw threads, to minor pickup repairs.