Either power down or go to the quick menu (hold down on android with 2 fingers). Select the spanner icon and then from this menu and then select the hand icon.
The touch will be disabled for a few seconds allowing you to wipe over the screen.
For the best clean, please use a microfiber cloth with an alcohol-based cleaner, we recommend Isocol www.isocol.com.au. Try to be more gentle on our Display Panels as they don't have hardened glass like the Classic & Pulse range.