Go to any poshish wala or service center, they will open seats and will take carpet and all stuff out. Service centre usually call it "General Service hay Sir G, interior cleaning 🧹 k saath".
They usually charge between 2,000 to 3,000 depending upon car and amount of work.
Then they wash all of them by Surf and other detergents.
Also they will wipe car cabin from inside. Also do car wash from outside.
This way it will be cleaned, then Mantain it by yourself at home DIY. Do vacuum regularly on each Sunday and also wipe your cabin, dashboard, door trims with slight wet wipes.
Also try to keep window closed to prevent dirt and dust entering with air via windows.