The herbs in the Herb Salad are not for flavoring, Wolf, but, supposedly, as prevention of medical issues - only there are only two that work that way (milk thistle and dandelion -if what they use is the root and not the entire plant because they don't say). The thing with herbs is that even though they are natural, they have medicinal properties, too and need to be respected as such.
The Herb Salad has:
dandelion - good for liver cleansing if it is the root but they don't say.
milk thistle - again, good as a liver tonic and cleanser but it needs to be an extract and they don't say if it is or not.
red clover: it has a high phytoestrogenic effect and it thins the blood - it is also believed to be good for cancer and as an anti-inflammatory but scientific evidence does not support this.
wheat grass: very nutritious: vitamins, amino acids and chlorophyll - all good things but you are better off giving the birds fresh food than feeding them just a bit of dried wheat grass
garlic: good antibacterial and an immune system booster but it's better if you give it fresh as flavoring in soft food
thyme: it's good for colds but it's also a diuretic which birds should NEVER get
parsley: way too high in oxalic acid for birds to consume regularly
lavender: good for calming but it's more the scent than the ingesting of the actual herb
marshmallow: 100% contraindicated with liver disease and it also absorbs liquid disproportionally contributing to dehydration
pau d'arco: this is not bad (it has quercetin and immune system boosters) BUT only the bark works and it should not be ingested, it's always used in decotions or infusions.
plantain: again, not bad, it's astringent and can be used for treating diarrhea BUT it needs to be infused.
chickweed: again, good herb (I raised my kids on an herbal tea which had chickweed, linden, star anise and chamomille) but it needs to be infused because otherwise, it acts as a diuretic (the second one found in the mix and a no-no with birds).
Gotta go now but I will continue tomorrow with the list (more bad to come