I'm talking chemicals in general. You may not know what exactly is in pledge. I know I dont but you want to risk the chance of damaging your paint at the same time.
For example dawn. Dawn is awesome to wash your car with if your trying to strip your wax or LSP. Dawn can also dry out your plastics on a car if used on a regular basis over time. When diluted properly if won't strip your wax but the dilution rate is very small with dawn because of abilities it has.
Soaps like four star, duragloss, CG, etc. are PH balanced which won't allow for stripping your LSP. Even these PH balanced soaps can strip or attempt to strip your LSP with the improper dilution.
If your making your own soap that's great as long as you have done the reading behind it to have the proper dilutions and ratios. Even "harsh chemicals" are safe when used properly. I am all for that. I love trying small companies products.
One more example is Simple Green. A great cleaner and decrease but if you spray it on bare aluminum it can actually etch it where something like meguires all purpose cleaner won't etch aluminum.