I have tested some cleaning techniques but I am unable to remove the small scratches, even if I use strong abrasive compounds with cotton cloths, they dont fade or disappear. It is possible to take them out in home or I should leave this small scratches to a pro?
See the scratches (lines) I am concerned of can be seen here:
Those appear polishing marks from someone who used a polish with too large a grit. a rouge cloth will usually remove them, just take time and be careful.
To remove the scratches completely you will also have to remove the same depth of silver which doesn't seem like a good idea to me. I would leave the scratches to be removed gradually each time you polish - and as a warning about using an over-abrasive polish (maybe the scratches were caused by that chalk slurry concoction you mentioned in another post?).
Deep scratches, simple answer, no. Polish or remove minor scratches with Jewelers Rouge Powder (paste). It has very little cutting action and cannot harm being used on 18K gold which is much softer metal. Jewelry Cleaning Cloth treated with Red Polishing Rouge is also helpful. Remember that one minute action of buffing and polishing wheels is equivalent to days of hand polishing. Just be patient and apply circular movements. In short, search for Jewelers Rouge. Kindest regards