You want to find something that will allow the toes to be spread apart to a comfortable stretch. It is really beneficial to work up flexibility so you can walk around in this state of comfortable stretch.
You can find toes spreaders at Daiso a Japanese store,. You may also find the foam they use for pedicures quite useful. Anything that allows the toes to be spread apart.
The Reflexes this exercise benefits: Top of head, eyes/ears, head, neck and shoulders. This is going to help with balance issues, circulation problems, and general foot pain.
Yours in good foot health,
Note: I do keep a small stock of these toe spreaders so if you have problems finding them, you can always get them here