Sharktooth grille repair

Acetone will melt the material. It is the main ingredient in pipe cleaner and adhesive.
The clear plastics adhesive works on abs, pvc, pcvc, etc.. due to its blend.
ABS spacific adhesive doesn't have the other components an wont glue pvc
properly. I'm no chemist but I do remember the days of black glue for black pipe (abs) and white glue for white pipe (pvc) .