I am getting ready to make my first batch. I have some Sassafras root bark that I was going steep in hot water with some other barks and herbs. I am now reading it may be carcinogenic. I have some Sarsaparilla root I could substitute. What kind of change would that make to the overall product? Would I use equal amounts?

Yes you can use the equal amount, One of mine friend did use to the equal amount and he got better experience as compare to the overall amount.