When you think of cleaning carpet you probably imagine a big machine that will spray cleanser and suck it back up removing all the dirt out of your carpet. This same task can be completed with a sponge mop. It will take longer and be more actual work, but the carpet will be clean.
Spray foaming carpet cleaner over a 3-foot-by-3-foot square area of carpet. Resolve and Woolite both make foaming carpet cleaners that are generally safe for most carpets. Always test the product on a small hidden area before applying it to your entire carpet.
Wet your sponge mop with hot water and wring it out well. The hot water will help the cleaner penetrate the carpet fibres and loosen up more soil and stains, but you don't want it dripping wet.
Use the sponge mop to scrub the cleaner deep into the carpet using forward and backward strokes. Wring the mop out into a bucket as it soaks up the cleaner and dirt. Rinse the mop when needed.
Continue this process until all of the carpet has been scrubbed and is lightly damp. To soak up more moisture, go over the carpet again with the mop, wringing it out often.
Allow the carpet to dry completely (4 to 5 hours). Then use your vacuum to lift the fibres and fluff your carpet, as well as to suck up any released dirt and residue from the cleaner.