I bought a gallon of “Safest Rust Remover” concentrate that makes five gallons of “fountain spray” but have not gotten around to buying the kiddie pool to place under the truck. I have a 120 volt AC fountain pump.

I saw the video here on Moparts of de-rusting the underside frame and axle assembly of the Ram by gently spraying the solution onto a rusty area and catching the solution in the kiddie pool and constantly recirculating with the fountain pump. Move the spray head progressively on to new rusty areas.

Safest Rust Remover allegedly can do this but EvapOrust liquid cannot.