poecilotheria metallica keeper

I have a neighbor who's home was built in the late 70's single level with PEX plumbing. I recently had to make a repair to a leaking line . I ended up replacing it with a Sharkbite T and some CPVC. I did the repair and ever since they have been experiencing noise in the AM when they first run the water. Since then I have tried to eliminate the noise : strapping the pipes, using insulation and bleeding the pipes several times. I got the best results by :draining all the water out of the pipes except for the water heater with the water shut off at the street. Then turning all the faucets on in the house then turning the water on letting it run for a few minutes till it ran smoothly then shut off the faucets. I waited till the next day to hear what happened and they told me it was better but this morning it was even worse than before. I have looked for air chambers both at his house and mine but haven't found any. The plumbing was silent before the repair I need to figure this out because the noise is bothering them and taking up my time having to try to solve this. I am of the opinion that I may have to install a water hammer arestor but the problem only occurs when they turn on the water and not shut it off .

In the am he walks it for an hour and it will go and pee every where but won't go poo till he brings it back in the house then it will go. I suggested that it might need to walk longer so he took it on a long walk for a bit over 2 hours the same thing happened why? What can he do to stop this ?