As an upholstery cleaner in Tampa FL I have watched several of Rachel's videos, some are great and some not so great. She has the right idea in her video about upholstery stain removal. One of my favorite go to cleaners in the home is a simple mixture of vinegar and water. It's great for getting out spots and spills and is pretty safe on most fabrics. It's really all you need for cleaning microfiber and other polyester based coverings. As mentioned in the video a lot of upholstery is covered in cotton based materials. This vinegar and water based solution works great on natural fibers as well. I still recommend doing a color fast test to make sure you don't have any die migration in your fabrics.
When using an upholstery stain remover on natural fibers like cotton it's important to test the covering to see if it is sensitive to cellulose browning. Some natural fibers like cotton, linen, and rayon are cellulose based fibers and are subject to browning if the fabric gets too wet. So be careful not to get them too wet while cleaning. If you need to spot clean make sure that after cleaning you dry the area quickly. I recommend a hair dryer on full power but low heat, if you have that setting. Drying the spot quickly after cleaning will greatly reduce your chance of browning.
If you have a grease based stain you can add a few drops of dish soap to your upholstery stain remover to help break down the grease and remove spot. Don't use a lot of soap or you will have a problem with dirt attracting residue and you ultimately be cleaning the spot again very soon.