Spears Manufacturing offers this for their threaded connections:
"Use a quality grade of thread sealant approved for plastics, such as Spears Blue 75.
CAUTION: Some sealant compound chemicals may cause stress cracking. 1 to 2 turns beyond finger tight is generally sufficient for plastic threaded connections. Do not over tighten."
In the past I've used 2 to 3 wraps of Teflon tape and a light coat of silicone...with cure time being the downside.
Now I follow Spears suggestions I've had no real issues.