Aelius wrote, " Aquilius was captured and executed by having molten gold poured down his throat as a punishment for Roman greed. "

None of the more contemporary sources mention the Crassus-molten gold story, but Cassius Dio (writing ?200 years later) comes up with this one:

""Crassus was among the fallen, either killed by one of his own men to prevent his being captured alive, or by the enemy when he had been severely wounded . . . there is a tradition which says that the Parthians in mockery poured molten gold into his mouth. For in spite of his great wealth, he was obsessed by money that he pitied as poor anyone unable to support an enrolled legion out of his own pocket." Dio, 40.27.

I betcha this is a bona fide case of Dio's confusing his sources, if Aelius is right (which he usually is)!