An arm and hammer would be used to break up something solid, but Arm & Hammer is also a brand of baking soda that can be used while breaking up cocaine. Once the cocaine is broken up, he then watches his kilos multiply by using the baking soda to thin out his coke. Since his kilos kiss and “make up” the Avon reference a few lines previously, become relevant again because Avon is a type of makeup.
Pusha T also uses a relationship metaphor to describe him manipulating his coke into two identical bricks (“a match made in heaven), where a reverend would carry out the marriage of the two.
Furthermore we could be looking at a triple entendre; He uses Avon for the make up and Arm & Hammer for the break up.
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