You can find most of those quite easily, although I had a bit of a hard time getting my hands on some of those enzymes. Been taking that recipe for a couple months now and my sense of smell has returned to full blast. For reference, I got COVID two times.
Are you saying that if I bought this detoxthespike thing it might help? Obviously nothing is certain, but unless I'm misreading your comment the above link you sent helped with your smell?
I'd say if your Dad is experiencing symptoms around his sense of smell, it wouldn't hurt to try! Most of the ingredients are easy to get online and are great for general health, regardless.
If you grab the ingredients (or a bottle), let me know how it goes! I've been recommending this concoction to people quite a bit lately, and I don't know if it's placebo or what, but it seems to help.
In either case, all the best for you and your father!