After few flights see many dust and sand attached to the rubble attaching the gimbal and the body...how will you guys clean this?

Canned Air??

Never had it, and I fly in dirty condx.  

hurricane O2 blower

Soft brush, camera cleaning blower, tweezer and damp clean cloth.

Air blower and use a small landing pad in future (or hand launch/land) to stop sand deposits etc getting into the gimbal on take off/landing.

Get a take off landing pad to avoid foreign debri to enter the drone.

Landing pad and canned air.