I’ve never used healing frequencies before, but I have heard of them! It would be really amazing if they worked because I would just play them all the time 
there’s always something I could heal from!
Oh, and with throat stuff - I know it isn’t strep-specific, but there’s a tea recipe around here somewhere that someone shared in a challenge entry. I don’t remember the challenge, nor the person who shared it, but I do remember the recipe! (I’ll go hunt for the link in a minute)
8oz of hot/warm water
2tbsp lemon juice
1tsp ground ginger (I used ground ginger but the recipe uses actual ginger)
1tbsp honey
Seriously, this was a lifesaver for me the last time I was sick. It felt so good on my throat, and it tasted good, too!
Edit: I found the link!