Work Emails and the ever Perplexing Aussie Slang

Wonder of wonders. Just when you think you have things figured out, you find another bit of Aussie slang to throw you for a loop. This phrase was at the end of the "cleaning out the refrigerator" message today:

I wish everyone a happy and safe long weekend, don’t forget to slip, slop and slap its going to be beautiful summer weather.

What does slip, slop and slap mean? I always ask poor Reino (the guy I sit next to at work) what all this stuff means, but I decided to Google it and I found this:

But this needs no explanation