I use all kinds of plants needed for a dense rainforest setup with my tokays. I do this since the 70s with no negative effect at all.
For smaller setups, plants with strong leaves should be preferred (like Dracaena, Platycerium, Pothos, Philodendron....) but in larger (300g and up) setups also delicate plants find their place and thrive.
Of course, you have to wash off pesticides before using plants. But do not worry about fertilizer. When necessary, you can use liquid (not pellets) fertilizer in your tokay tanks without any need for concerns.
Best
Ingo