Kimbo ~ Willow is ok if it is from Goat, Pussy or Weeping Willow trees.
The following woods are deemed Parrot 'safe, but there are exceptions within given categories ~
Here is a partial list:
Alder, Almond, Apple, Apricot, Ash, Aspen, Bamboo, Beech, Birch, Cherry,Citrus, Cork Oak, Cottonwood, Dogwood, Elm, Eucalyptus, Fig Species, Fir, Fruitless Mulberry, Grape Vines, Hickory, Manzanita, Maple, Mediterranean Laurel, Mesquite (remove thorns), Mimosa, Mulberry, Nut (except Chestnut & Oak), Oak (wood only, no bark or leaves), Palm, Papaya, Pear, Pecan, Pine, Poplar, Rose, Sassafras, Sequoia (redwood, no bark), Spruce, Sweet Gum, Sycamore,Walnut (Black Walnut may be dangerous)
Wash all wood in a bleach solution, rinse then for small branches bake in
oven at 250 for about 1 hour and for large branches wash, rinse and dry in direct sun.
I'm fairly conservative in what my parrots consume, and some 'natural treats may safely cross over but I lean toward NOT using other animal snacks and treats for parrots. Your bird should be satisfied with natural fruit/nut/pellet treats and you don't have to worry about unsafe ingredients or additives