@Patty_Melt It’s not wood. It’s cellulose, generally from bamboo. (which is a grass) But if you eat a carrot, you are eating cellulose. It’s the basic plant cell. There is nothing inherently wrong about it, but if you think you are getting 100% and it’s loads cheaper than the others on the shelf, look for the filler. It will be palm oil, or just listed at vegetable fat. Also, those cheap meat balls might also have cellulose from bamboo, so if you think you are buying 100% meatballs, look at the packaging. There is always some sort of filler in meatballs, but they have to list the % of meat. Same with fish pudding or fish cakes or fish fingers. They bulk those out with tapioca or some other cheap starch. Keep an eye on the % of fish in the product and buy one that tastes good to you. Nothing wrong with those fillers. They won’t hurt you, but, perhaps, it isn’t as good a source of protein you thought you were getting.
As far as soaps go, I think you are referring to detergents. Technically, a bit different. You don’t want to shower with a 100% surfactant. (like SLS) You’d strip your skin dry and probably develop nasty skin conditions. So, they fill those with bulking agents like propylene glycol, water, actual saponified and unsaponified fats (which are true soaps and oils) and pH stabilisers like citric acid. There are some really shit laundry detergents on the market, but you can usually rely on consumer reports to find a reliable one that works for your machine, the temperature you like to wash your clothes in, and the type of water you have. I’d never use powdered if I had hard water. You need to use less if you have a soft water tank because rinsing cycles aren’t as effective. Everytime I’ve moved I’ve had to change how I do my clothes because what seemed to work in one machine and one type water didn’t in the new place. I discovered laundry boosters in the 90’s as well that contain sodium carbonate peroxyhydrate. It takes the cleaning and laundry game up a notch.