How does this strategy work, you pay full tax in Malta, then via DTT you inform paid taxes in the country where the holding company is, then go back to malta and ask for a tax refund, due to non-residency etc?
The Malta company first pays the full 35% corporate tax in Malta. Once that's done, the parent company applies for a tax rebate of up to 6/7 (six sevenths). 35*(6/7)=30. As long as the shareholder lives up to the requirement of being non-resident and non-domiciled, the request is approved.
If you are a foreigner living in Malta, you only fulfill one of those two criteria: you are non-domiciled, but you are resident. So residents set up companies which qualify as tax resident through incorporation (such as UK), or simply rely lack of enforcement from IRD and use non-resident companies (such as BVI).
So if the Malta company paid 70,000 EUR in corporate tax against 200,000 EUR profits, the parent company would get 60,000 EUR back. This makes your net tax rate 5%.
In many, but not all, cases the tax rebate is not in scope for corporate income tax for the holding company. I'm not familiar enough with Mexico to comment on that specifically.
To use the money for yourself, people (expats in Malta) often pay themselves a tiny salary of around 9,000 EUR from the Malta company which is not subject to tax. The rest of the money, they take out from the parent company one way or another. There are different, creative ways to do that as a non-domiciled resident.
Technically, if you are a non-resident of Malta, you don't even need a holding company since you, as a natural person, satisfy the criteria. But then you have a local tax burden to worry about. The structure works best if you are resident in Malta, or can pay yourself money from the holding company in a tax efficient way.