How would you say “trickles down” using American slang?

"Trickle down" in reference to money IS slang, or at least an idiom.

If I'm trying to be funny, I might make a "skeet skeet" reference, but that actually means squirt, not trickling down. I might also make a joke about "dribbling" because that sounds vaguely dirty, If I'm not trying to crack jokes or be inappropriate on purpose, I'm just saying "trickle down" like everyone else has posted. Because of "trickle-down economics" from the 80s, it's a well known phrase in US English.

"Trickles down". We don't really have a slang term or word for it.

I mean trickle down is already the slang

'Trickle down', as in 'trickle-down economics' is already a phrasal verb. How much more informal do you need it?

Trickle down as in trickle down economics is sometimes referred to as Reaganomics because it was Regan’s economic policies. Trickle down is just standard speech doesn’t really have slang.

You wouldn't have a slang for this because it's not something that ever needs to be commonly referenced. It's a political grift phrase to dogwhistle for lower taxes.

There’s no specific slang term for that, we just say trickle down

I don't know if there's a slang term for that.  What's the context?

Voodoo economics

I would just say trickles down. The term "trickle-down economics" is pretty common in the US to describe certain policies that are seen to favor the wealthy.