i believe that after some serious heating treatment the hexane will completely evaporate, an evaporation test to see if any residuals are left behind is a must, but other than that, it has a lower boiling point than ethanol (69 Celsius or 156 Fahrenheit) and its used widely on extractions and reactions that involve strong bases since its hard to deprotonate it, i would go for something like 90 Celsius for 3 hours to be completely  worriless.

also a new method with zeolite i found on a paper reporting 72% Δ9 is simply using anhydrous hexane as a medium, now am not sure how yet, but it appears as if hexane somehow contributes in the minimization of Δ9 degradation, not sure if its just oxidation related or another factor, ill check if it works but am not sure it would be appropriate to upload here since it requires a reflux setup and a heating mantle.

keep it safe and DYOR.