Can I use onion salt in place of onion powder and how much would you use?

Yes, you can use onion salt in place of onion powder, but you should adjust the quantity due to the added salt content. A general guideline is to use about half the amount of onion salt as you would onion powder, and reduce any additional salt in the recipe accordingly. For example, if a recipe calls for 1 teaspoon of onion powder, use about ½ teaspoon of onion salt. Always taste and adjust to your preference.