Why waste time with a toothbrush for 2 hours! Just put it in the dishwasher. If there are electrical parts, use a little regular detergent. If it is plastic only, use aggressive dishwasher tablets.
If you dont have a dishwasher, partly fill the bathtub with warm water. Mix in some detergent. Shake the device to be cleaned vigorously under water.
Do not be shy.
Shake to dry. Then leave propped up at some angle to drip/drain dry for half a day, then turn over, shake, and leave to dry again.
How long for? Take a wet teashirt (spun dry) out of the washing machine. Hang it up in the same room as the device you are drying. When the t-shirt is dry, then so it your device.
I have cleaned keyboards, mice, and mainboards like this. I do not use this process for CD drives or HDDs.