Cheap carpet cleaning methods/cleaner recommendations

[Boltonlass1972]

We have a dog and now my house smells 'doggy' as he sleeps in random places on the carpet.
I can't afford a fifty million quid carpet cleaner, or even afford much at all. I've looked at reviews of Vax's cheapest cleaner but wondered if the goddesses of MN had any bright ideas or recommendations of cleaning carpets on the cheap (methods or cheap cleaners) please?
I have also bought some bicarb... not sure what I might do with it yet.

Dog bed?

Yes, we had one when he was a pup but didn't replace it when he grew out of it. Funnily enough have just been having a conversation with hubster about getting one. Thing is, he will lie down in different places depending on what he feels like. Sometimes on his blanket on the sofa, sometimes on the floor in the lounge, sometimes in the hall if it's sunny.

Hire a Rug Doctor for a weekend? Use liquid laundry detergent instead of the expensive Rug Doctor stuff - about half a capful per tank of water.

My method is a bit labour intensive but cheap as chips.

Bucket of warm water
Bottle of Star Drops
Softish scrubbing brush

Generous squirt of star drops into warm water and swish vigorously until very foamy.

Dip brush into foam and a tiny bit of water (don't get brush too wet) and gently scrub carpet all over.

If necessary, you might need to spray a little stain remover on stubborn marks.

Leave to dry, then vacuum - freshens carpet a treat.

Ooh, stardrops! My mum used to use that when i was a kid. Never used it myself, but you'd recommend? Thanks for the tip about liquid laundry detergent too.. had never thought of that as an alternative.

Eyebrows' method is a good one - it can be a lot of work though. I once cleaned the kitchen carpet (yes, kitchen carpet) in a rented flat using Stardrops before we moved out. It came up brilliantly.