We use Coopex around our house to make a barrier. You get it in a satchet and mix it with water in a pump sprayer then just spray it under the eves and also at base of walls around the house and garden. I reckon two or three satchets would do a smallish house or maybe 4 for a larger house.
I always use the strongest mix mentioned on the packet.
Can get it from Bunnings or any other hardware. It's about $10 ea.
Goodluck mate.

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Subaruless