You can use orbital sanding machine but many sand paper it will take

Cost of sand paper is 12 per 1$ in PK. I think thats fine....

Moreover it's not possible to remove old paint completely at a deeper level

Works with only lime for emulsion you can try pressure washer kzfaq.info/get/bejne/jcx4nsqEmLfamGQ.html

No if we do so it will not remove the particles from wall quickly

@@diyguide4049 any tip for preventing the dust plz?

@@nirpaLj There is Dust Shroud available in market like this amzn.to/3zKpVnF but its costlier and won't fit for this brush space. In such case you can wet the wall and use. Only thing is it will take bit extra time but you can achieve with minimal dust.

kzfaq.info/get/bejne/ecV3gs1euMqVl5s.htmlsi=_ObNdzILOr-CyArd description of this video has the details please check