I have to the author of this video on how to clean a microfiber couch some credit. No pun intended, but the credit card trick is a new one for me. I've cleaned hundreds of microfiber couches and I have never thought to scrap one with a credit card as an extraction method to get heavy soil out of the fabric.
Microfiber is a polyester based material that is durable soft and cleans easily. One of the major problems with polyester is that it easily absorbs oils and grease. That's why a microfiber couch gets heavily soiled where we repeatedly rest our arms and head. Oils from our hair and skin are absorbed into the fabric and quickly build up. It's important to clean your microfiber based upholstery on a regular basis to prevent oil build up.
I usually recommend cleaning microfiber with some carbonated water and some vinegar or rubbing alcohol added, but carbonated water does a great job of cleaning it on it's own. As a professional upholstery cleaner in Tampa FL I have seen hundreds of heavily soiled microfiber sofas that have required a little extra to get them clean. This video on how to clean a microfiber couch mentions using some denatured alcohol as a cleaning agent. It can help remove some of the soil but for real greasy spots I recommend using carbonated water and a few drops of dish washing soap.
I would also suggest skipping the credit card trick and use a small wet dry vacuum to remove the excess moisture and soil. You can by a 2 gallon wet/dry vac at Home Depot or Lowe's. It will work a lot better and is a lot easier to use.