I have no idea about non residents using CESU.
I remember when it started and all I thought one had to do 'then' was have a french bank account so that the right amount could be debited from the bank account with the charges included on it, and the employee, got the amount they were entitled to.
Then ofcourse, the employer, could claim against their tax bill, but if one doesn't pay tax in France, then one doesn't pay tax in France, then what is debited from one's account, then that's the bill.
Just how I thought it worked, but I may be wrong....... I often am.
AND at the time, it seemed like a cheaper way of employing someone than using a fully registered artisan.
I seem to remember that there were changes in the recent past and that is for the OP to look up isn't it, or just go to the pages jaunes and get an artisan, who would be more costly?