I HIGHLY suggest DON'T use AQ salt regularly, and if needed I can get most people here to help you in that regards-
Using AQ salt regularly is, in a sense (and easier to explain this way) dehydrating them. Over use, over exposure can and do cause kidney and liver failures, as well as bacteria and the fish can become resistant to the beneficial properties the salt has when treating for an illness- so the salt will become less effective, or none at all when it is actually needed.
Please, I ask not to use AQ salt on a regular basis as it it will catch up to them and can cause harm/death very easily. Bettas are freshwater fish, not brackish- so having them in salt only damages them and adds no benefits.
It does not soothe them, it does not prevent illnesses, it does not help keep them healthy, it has no affect on their coloration- good protein enriched food, warm water, weekly water changes will keep sickness away, make them happy and healthy and brighten their colors. Using something dangerous such as salt to make up for lack of proper water changes, nutrition, etc is doing more harm then good, I'm sorry.
Also, don't use bacterial supplements unless you are cycling and understand what they do- I've only seen them do more harm then good when just tossed in. Your tank will build up it's own beneficial bacteria on it's own.