Pivoted the valid options into the interface and used the selections to filter the results:
And ([Primary Type] = [#2] Or [Secondary Type] = [#2])
My solution is attached! Good practice with the app interface tools.
I feel really old now having grew up with pokemon and now not knowing even a third of these! Decided to add an extra option to allow the user to decide if they wanted to search the secondary type or not.
Looking at the solution, I should really remember to use the IN command next time I use a list box. Makes it easier.