What is this buying you?
Properly torqued Nylocks or steel locknuts will not loosen...the engineers designed the structure to use the correct bolts for the flight loads. Same for castellated nuts.
Loctite is not an anti-seize, either.
I'm not an A&P, but I'd say use what the plans call for, and follow best practices (AC 43.13), and avoid untried "solutions".
Torque correctly, mark with Torque-seal, and move on.
ETA: From the description of Blue Loctite:
"The product cures when confined in the absence of air between close fitting metal surfaces." (N.B. Metal, not metal and nylon)
"Not Recommended For
Use on plastic parts, particularly thermoplastic materials where stress cracking of the plastic could result ."
I don't know if Nylon counts as plastic, but I'd avoid mixing the two. Who knows what Blue Loctite will do in the long term to the nylon inserts?