Cleaned Tank Now Smell Won't Go

Cross posted from new fish keepers as I've had no reply.
Hello I am totally new to tropical fish but reading lots. I have bought a 2nd hand 75 litre tank. It came with gravel , filter and an ornament. We were scared of passing anything nasty onto the new fish so we cleaned the tank with baby bottle sterilising tablets. It has been rinsed out and had the water changed twice but when I open the l can still smell a chlorine type smell. Should I just go ahead and start cycling it or do I need to do something else?