When watering succulent arrangements or cacti in pots without drainage, the most important thing to bear in mind is to apply water in a controlled manner and to allow the soil to dry out in between waterings.
We generally prefer to use a directional spray bottle with the nozzle set on the stream setting. Aim the water stream around the base of the succulent and on the top of the soil or gravel. Apply just enough water so that the roots can soak up moisture but not so much that the roots would be sitting in water.
Spritzing your succulent is not ideal, the objective is to direct water at the base of the plant where the roots can take up what they require.
As a general rule of thumb, we recommend a once a fortnight watering cycle for succulents and once a month for cacti. These recommendations can vary depending on sunlight received and pot depth. The main key is not to over-water. Please adjust according to your plants environs