Never has this happen, painted wood siding (paint is 2years old and in great shape, its ok with SH).
is coated in pollen that has been sitting there and it doesn’t budge unless high pressure or brushing is used. After i showed the owner she confirmed last company had to brush it.
I’ve cleaned a lot of wood siding but never had an issue with pollen being hard to get off.
Was it older siding that had a lot of grooves and divots where it was getting in and landing?