How clean the flatbed printer encoder strip and sensor

The structure for the carriage:
1. encoder strip 2. There is a U holder for the encoder strip if you look along the encoder strip. This is sensor.

Step 2. Two holes for putting through the encoder strip.

Encoder strip picture.

How to clean:
Cut off the power.
Take out the encoder strip.
Find a thin flexiable material and cotton.
Cross the cotton onto the flexiable material.This is called cleaning bar.
Put throuth the cleaning bar to the encoder strip.
Push and pull through it.