Sound is indeed extremely powerful! The problem with this though is that the human is the one who choses the sound and this may not be what is what the crystal needs or resonates with. But I guess if you intuit... and I doubt it'd hurt :)
Personally I prefer to use a tuning fork over a singing bowl or gong for this particular purpose.
There's this Japanese woman who has posted a lot of clips on YouTube and uses a lot of different tuning forks. She works with them and other instruments.
Even from these clips and through speakers the effect is extremely powerful!
Her energy is also very strong and high.
This is her channel:
MIYUKI Yoga&Meditation&Tuning Forks