There is also a Cross Sales Manager on the Marketing Menu where you can set multiple Cross Sales at once.
Cross sales must be configured on your product templates for this to work.
Click the product on the left to move it into the Selected Products list on the right. Ctrl+ Click to select multiple products at once.
A Reciprocal cross sale means that the active product 454 Horse Power will display Cappuccino & Espresso Spoons as a cross sale, and Cappuccino & Espresso Spoons will display 454 Horse Power.