Eric wrote:

Almonds are in the same family as peaches and plums. I can get plum leaves
for free. Would they work?

No, this probably means the sea almond Terminalia catappa L.
(Combretaceae), which is related to the white mangrove, Lagencularia
racemosa and common around the Indian ocean. The fruits are edible and
have an almond like flavour (hence the name), the lumber is used by
carpenters and the bark for leather making. The leaves contain tannic
acids, flavonoids and a host of other active compounds (most not
identified), with mildly fungizidal and bacteriostatic effect. A tea
from those leaves can be used by humans internally for intestinal
problems and externally for skin infections. In the aquarium 1-2 leaves
per 100 l (25 gal) are used to prevent mold formation on fish eggs and
to treat skine and slime infections in fishes. They also make a nice
food for shrimps, cat fish and the like, which feed on vegetables. So
largely you can compare the sea almond with tee tree in its effects.

If you find the leaves too expensive, you can grow your own sea almond
tree, provided you can ensure a minimum winter temperature of 15 degrees
Celsius. The tree reaches a hight of about 10 m and is not very
demanding to grow.