Correction on a sentence:

I know a couple preteens who could have benefited from the use of a vibrator so they stopped using their electronic toothbrushes (I was told about their toothbrush adventures by them).

This sounds like I provided vibrators when I did not.

I know a couple preteens who could have benefited from the use of a vibrator since they were using their electronic toothbrushes instead (I was told about their toothbrush adventures by them).

I just told them have fun but don't let your parents know and to wash the toothbrushes after. One already did, the other didn't.