Sinse you have tendonitis i dont think increasing your tendon and muscle strength will make it go away.
I have had friends get deep tissue massages for it, but anti inflamatory drugs are more widely used.
I had fallen 12 feet at work and landed at an awkward position slightly tearing a couple ligaments in my knee. After a couple months my knee didnt get any better so i began asking around on sports forums what people do to put their bodies back together.
This was a forum with a few pro level athletes and every one of them said to get prolotherapy done to my knee.
I did, and it is about 95% back to normal. I needed 2 more treatments, but put it off.
Here is a quote from Prolotherapy.com:
It is important to reemphasize that proliferative therapy is NOT a pain treatment-it's a strengthening treatment. Thus, strengthening is the main effect; the reduction of pain is a side effect!
I sent my dad to my doc for his carpel tunnel, and well, he only went 2 times but he says it is about 50% better than it was.
If you meet with a doc and he says he can treat the problem, it will work.
Ins doesnt cover it though, and each treatment for my knee was 150 bucks, but looking back i would have paid 1000.
P.S. One more thing. 6 months ago i thought i was getting or had tendonitis. It is always in the back of my mind being a mason. I was at my chiropractor and mentioned to him that my elbow hurt. He did some range of movement test or something and said it wasnt. Long story short he gave my arm a weird little twist, my elbow cracked, and the pain was gone the next day at work.
May or may not be usefull hahaha.