Ever buy a comb that has sharp teeth? Painful, right?
Here is a quick and easy way to round the edges.
Turn your stove-top up to somewhere between low-medium or higher. The lower, the better.
Different plastics have different melting temperatures so you’ll have to very closely observe the process.
Disclaimer: DO NOT BURN YOURSELF and DO NOT CATCH ANYTHING ON FIRE!
A few inches above the heat, slowly move the comb about (back and forth, or a circular motion) with the teeth pointed towards the heat source.
VERY carefully observe for teeth-edges to start rounding, and when it ‘looks right’ (i.e. gently rounded) to you, move the comb away from the heat source. Blow gently on them if you need.
Remember to turn off the heat source.
Don’t touch any hot spots until they cool down! And good luck!