Do you have any evidence?if youre talking about the inlet and outlet in the tank...then NOPE- youll kill everything in there
+1 for krylon and +1 on what davocean wrote. I spraypainted a rear plastic panel in my Chevy Cavalier (it wasn't a rice mod to get additional 15HP from my car, it was so scratched I had to do it) and it still holds well and doesn't chip (after 2 years). I sanded the whole thing with 1000 wet sand paper, used a primer spray, few coats of krylon (sanding between coats) and finished with clear gloss krylon. It works really good and krylon is cheapest spray you can buy.I would be sure to scuff/sand any smooth plastics/PVC for best bond.
Those scotch brite pads work great for that.