We use a dry film lube of Al-Al threads per MIL-PRF-46010. It is cured on the threads, and does not come off from handling or installation of threads. Might do the trick for you.
Sample callout:
APPLY EVERLUBE 9002 IAW MIL-PRF-46010 TO THE THREADS, .0003 TO .0005 THICK. CURE AT 400 DEG F +/- 15...