Neglected Hot Tub

I acquired a good condition tub that has been drained for about a year. I notice a funky smell from the tub when empty. I’m thinking of filling it up and running ahh-some in it. I read some where they recommend to super chlorinate it also to kill any bacteria in. Then drain and fill and start fresh.

Does sound about right or do you recommend anything else to do to it?

Thank you!