Kelly is right, keep up with the salt baths for now. But don't over do it...salt can obstruct their osmoregulation (which is basically the balance of water and salts in their body) give a few days in between if you decide to do it more than once a week. Do you leave the salt in the tank? This is probably not a good idea, I know some people do do it, but in my experience I have learned that salt dips for 5 minutes at a time are better then leaving salt in the tank. Again, due to the fact that they are not equipped to osmoregulate in salt water. The concentration you are using seems fine, some people put as much as 1 tbs per gallon for a dips if you do decide to go that route.
Also, Kelly is right about no medication until you need it. Monitor the situation, if you feel you are getting no where with the salt baths are you fear the worse then do so...but you should be very sure. Since it does remove oxygen you should not use it in a small non aerated tank. I would wait until your new tank comes along
Hopefully he will cure up nicely without having to use medication
I had to use it on my betta before, it worked fine, but his fin was falling off in chunks and nothing else worked
I just had to make sure he had lots of oxygen.
I am sure your betta will LOVE his new tank! He will feel quite spoiled I am sure