It is enough to wipe a bottom tray with paper towels or a soft cloth soaked in medical alcohol. Repeat the process several times until the fabric is clean, then rinse the container with clean water and leave to dry.
An upper pan requires more thorough treatment due to an integrated mesh. It is recommended to use alcohol and a nylon brush for this. Apply alcohol to the entire surface of the screen (you can spray it or just wipe it with a copiously dampened towel) and rub it with a brush until it is clean. After that, the upper pan can be washed with soapy water. Just be careful that there are no soap pieces left on the mesh.
Harvest More recommends an alternative way to clean mesh screens. Place one of them in the freezer for a quarter of an hour and clean the frozen plant particles with a brush. It’ll really speed up the process.