At a time when cleaning is essential.

I would want a written letter from the Company explaining exactly why? If it's to protect their workers from your Dad well that's taking it to extremes; has he been anywhere? If it's to protect their workers my response is that they aren't doing a particularly good job over all then! if they are worried about contamination. What happened to the human aspect?
I will say again:
Use BOILED water with a mix of laundry powder and domestos: wipe all surfaces regularly allow to air dry. BOIL the clothes used.
Wipe under taps, under Council bin lids, handles and where anyone else may have left the Virus. It doesn't like boiled launder water.
Metholated spirits will work. It breaks down the fat on the outside of the Virus, therefore drowning the little blighter . If gloves are worn and in my opinion these are dangerous as they rarely get washed often enough and will end up in landfill: taking them off correctly is important. Having worked in clean rooms my DH has been explaining to anyone wearing gloves anywhere

the protocol. One-use gloves are worse than even Marigolds which can be boiled after use.
Katejo - tell your brother to carry out good cleaning regime, including the car doors/boot handles, steering wheel and gear stick if he drives between places. Wipe the door handles at your dad's place going in and on the way out - backwards as it is. Maybe provide your Dad with a bowl of water/laundry powder and a cloth so that he can wipe as he goes along ? Don't forget the handle of the hoovery-thingy, dustpans, brushes etc.. Also the telephone and door bell where appropriate.