Decal override is used primarily for raycast weapons (guns), not for thrown weapons like a molotov. The flak (grenades, rockets, etc) in FPSC are not designed to be a lingering thing, but rather they explode, do some damage, and that's about the extent of things.
I know vanilla FPSC now has a particle system in place. Perhaps you can ask around about using that system to get your molotov working.
The one and only,
Only those who sow the seeds of their desires will reap their benefits later.
However, I have seeds of my own to tend to. I don't have time to be someone else's watering can.