Welcome to the site!
Hehehe good luck if you are planting them for decoration
Redfoots eat literally anything. My guy even chews on plastic pots in his enclosure :flick: I just aim for non-edible items in his indoor cage, but aim for edible stuff in his outdoor pen (leafy greens mostly). Sorry I don't have any good suggestions for decorative plants
I don't know much about how much checmicals make it inside the actual plants, but whenever I've used live plants for animals (that aren't likely to eat them), I take them out of their pots (leaving as much soil behind) and rinse the root system in regular water, and rinse the above ground parts in soapy water (dishsoap), followed by a good clean rinse. I then give them a 'quarantine' period of about a month or so, misting them with warm water and watering them in their new soil, before finally adding them to the enclosure