Cat wee stink - help!

[shockedballoon]

Our 9month old DCat is not loving the litter tray since he's been allowed out & combined with a dicky tummy due to food intolerances (working on that) means we've had a lot of accidents. One area in particular. I've used nearly an entire 500ml bottle of Simple Solution cat extreme stain and odour remover, and if anything it smells worse. It's not quite dry yet, but not sure that'll make much difference.
I've borrowed my friends Vax to clean the carpet with, but wondered if anyone had any other ideas? My lounge stinks like a neglected litter tray ☹

Has he been neutered?

As for products, most recently I've used "Urine Off" from ZooPlus for wee clean up and it seems to have worked. Our issue was not so major though...

I think there probably comes a point when carpet is irreparably stinky. If Simple Solution and a very strong Zoflora solution don't help then you're doomed. Although I would also try a solution of bio washing liquid.

You may just have to get rid of the carpet. Vinyl is much less problem.

He has been neutered- we kept him in until 5 and a half months then got him neutered and he's been allowed out since. He wasn't the easiest to litter tray train, but he was reliable in the end. Once he was allowed out he very rarely went in the tray rather outside, but recently he's been going in the lounge. We keep him in locked in the lounge at night and he has free access to his litter tray in the conservatory where it's always been. He's now locked in the conservatory overnight as this has less nooks and crannies, however it's also carpeted 😏
I would gladly get rid of the carpet, but we're having an extension next year which will totally change the lounge/conservatory area and I can't afford to waste money on temporary flooring. I looked under the carpet and really can't pull it up. Argh! Pleeeease say I don't have to live with this stench until then - I can't have anyone round it's so embarrassing!!

Surgical spirit is worth helping for the smell. If he has a favourite spot, it might be worth trying litter training pads.

Is it carpet? I found most of the smell was in the underlay so I bought some more. Cleaned the carpet and put fresh underlay in and it smells so much better!

Update: gave up on the carpet. Tried just removing the underlay and re-treating the actual carpet, apart from one area in the lounge it didn't work and still stank. Attacked the offending areas with scissors and now have chunks hacked out in the conservatory and in the lounge behind the telly. Saturated the floorboards with enzyme stuff which has now dried. Looks crap but smells sooooooo much better, which I just abt can cope with. Conservatory is worst, about a 1/4 of the carpet is gone but I've just papered over with incontinence sheets and 3 litter trays. Bloody good job DCat is cute!!