Before you try anything like loctite, why don’t you just install the new plugs and see if they hold. I would suggest that you use a torque wrench on the plugs. If you don’t have one, they aren’t too expensive to get at AutoZone or one of the car parts places, about $20 or so. Don’t bother with Craftsman, they aren’t worth the money.
Save the loctite in case the new plugs don’t hold when properly torqued. I believe the proper torque is somewhere between 11 and 20 ft lbs.
If you use anti-seize, and you should unless the plugs are plated, be sure to use the stuff made for spark plugs, the zinc oxide based product. Do not use copper anti-seize, they will back out then. The aluminum, being the more active metal when next to copper will erode. You want all erosion to be in the anti-seize, not in the aluminum threads.