Average joe has no problem buying anything legal online. Naptha, lye etc. If you stick to a small business, they have very little reason to call any authorities on you because they really really want your business. There are lots of small companies offering lye, and there are thousands of at-home soap makers and dozens of small soap businesses that need to buy lye. They can't tell what your intentions are by your credit card number.
The real issue is later on....what if something bad happened? How would you protest your innocence when you bought 10 bad things all in the same week, all with your credit card?
Acacia bark is illegal in the USA, same as MHRB is. It is just more under the radar at the moment. Don't do what the shroomery kids did/do and buy everything together at once on amazon.
Some other things are perfectly safe...caapi, amanita muscaria, mandrake root....all good