How To Get Rid Of Puppy Poo Smells?

I have a less than 4 month old Westie puppy, and we’ve been continuing his housetraining since we got him at 9 weeks. He cant go out til next week when his vaccination course is over, but we just cant get rid of the 6 weeks accumulated smells of mostly poo.
We have pet odour/stain remover from the pet shop (we have no stains, just smells) and we use febreeze on the furniture etc and regularly hoover.
So, how can I get rid of these smells?
If someone suggests to shampoo my carpets, can you pls suggest what do I do/use and how do I do it etc and products that are available in the UK only please.
Just so you know:
Yes, I clean regularly.
No, the puppy himself doesnt really smell (again, cant bathe him until next week but we use cleansing puppy wipes to keep on top of it)
No, I dont want to get rid of carpets for wooden floors/lino.
Yes, I plan to retrain him to go outside, but we still need to shift the smell in the house.
Yes, we pick up dirty puppy pads/paper as soon as he goes.
We are continuing housetraining him because he still has accidents (as he had a stomach illness from 10-12 weeks old so his previous paper training was kinda forgotten by week 13 – this is also the reason why his injection course was so late so no lectures on should have got him done before 12 weeks please).
Thanks in advance
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