It is more than year of time we can go with monero to mine on CPU but recently even cheap coins are also not worth to mine with the CPU. I am not sure why you have shared whattomine to him.
There GPU, ASIC are available select the best algorithms and card you own!
My final words to op. Please do not go with CPU mining even you will not able to get the money for electricity consumed for the mining. Simply you are wasting your time. Go with Rx 470 cards and start mining.
These are obviously not his computers nor does he pay for their electricity so whether or not its worth it doesn't enter the equation, he's going to bog down some unsuspecting nursing homes computers anyways.