No worries. First, I did want to relay some of my experience during my time as a beginner soaper relying heavily on BB's recipes. The first batch of soap I made was a BB recipe, which included avocado butter. Now, there is nothing wring with avocado butter, but it's quite expensive. But, not knowing a whole lot about swapping out less expensive yet comparable ingredients, I bought the avocado butter from BB and made the soap. It was a small quantity of soap, but the avocado butter, at $12.99 for a pound, made it a somewhat expensive batch of soap. I didn't know anything about fatty acid profiles, and I trusted BB's expertise.
That said, now that I've had a good look at the recipe you asked about, it's a decent recipe, though 25% CO is 5% more than I'd be comfortable with as a facial bar. Second, at 5%, the tamanu oil would barely give the soap noticeable character. Third, the FA (fatty acid) profile of tamanu oil is very similar to the much less expensive rice bran oil. I created a FA profile spreadsheet when I first started to analyze ingredients and make a real go at making a better bar of soap.
View attachment 56370
That tells me that I can easily swap out the two fats, save some money, and generally get the same benefit. Keep in mind that any other characteristics of tamanu oil will be lost in the harsh environment of cp soap-making. That, for me, is the big ugly bummer about soap-making truths. Which is that oils that have unique benefits as a leave-on product (like tamanu) are lost in soap for two reasons: the saponification process loses certain properties and because soap is a wash-off product the skin does not have time to absorb those lovely properties.
And that stinks because tamanu oil, as I mentioned, is lovely oil. In fact, after my reply last night, which reminded me of how much I love tamanu, after washing my face, I applied a thin layer to my face. This morning my skin is so soft, supple, and hydrated.
The same, sadly, goes for activated charcoal. Any benefit your skin might gain from the product, because it spends so little time with your skin, just washes down the drain. It's great label appeal. And heck, a black bar of soap looks so cool!
Having said all that, I'd like to add a caveat that I learned about making soap by making soap. So on the one hand I'm more of an "give it a shot and see how it goes" than tell people what to do/what not to do. But on the other hand, I'd like to spare you the expense of buying tamanu oil to put in soap. Will it make a good bar of soap? Yes, most definitely. In fact, I think I might make one bar of soap using tamanu and see what is does in soap. But I would not make a habit of relying on tamanu in soap for the reasons I noted above.
I do want to encourage you to keep making soap, and experimenting with different fats/oils/butters. That's how we gain experience.
To wrap up, I am of two minds about BB. They offer a great starting point for beginning soap makers. That batch of soap I told you about? It's cured for well over a year and its a wonderful bar of soap. In fact, I use it on my face because it's so lovely. But I could have made the same bar of soap at half the cost using shea butter instead of avocado butter.
Anyway, that's a lot of words to say "go for it but proceed with a few things in mind."