Most RV antifreeze is propylene glycol and ethanol. Both of these molecules are considered polar.
Garlon 3 should dissolve in RV antifreeze. Garlon 3 is an amine form of Troclopyr. It is a polar molecule, so it should dissolve fine in ethanol and propylene glycol. The ester form of Troclopyr should dissolve in alcohol because alcohol has a polar side and a nonpolar side. The ester form of Troclopyr would dissolve better in diesel.
Arsenal is amazapyr, which Google says is polar. It should dissolve fine in water, alcohol, and propylene glycol.
Well I could not go today (schedule change) but I made a mixture to try. I looked in garage and could not find any spare antifreeze but I found another thing to try: Windshield wiper fluid! Says it is good to -20 so we will see!
Mixed 50% triclopyr (garlon 3a), 40% windshield fluid & 10% imazapyr (arsenal AC). All are water soluble polar molecules so we will see!!